Strained germanium hole spin qubits are promising for quantum computing,but the devices hosting these qubits face challenges from high interface trap density,which originates from the naturally oxidized surface of the...Strained germanium hole spin qubits are promising for quantum computing,but the devices hosting these qubits face challenges from high interface trap density,which originates from the naturally oxidized surface of the wafer.These traps can degrade the device stability and cause an excessively high threshold voltage.Surface passivation is regarded as an effective method to mitigate these impacts.In this study,we perform low-thermal-budget chemical passivation using the nitric acid oxidation of silicon method on the surface of strained germanium devices and investigate the impact of passivation on the device stability.The results demonstrate that surface passivation effectively reduces the interface defect density.This not only improves the stability of the device's threshold voltage but also enhances its long-term static stability.Furthermore,we construct a band diagram of hole surface tunneling at the static operating point to gain a deeper understanding of the physical mechanism through which passivation affects the device stability.This study provides valuable insights for future optimization of strained Ge-based quantum devices and advances our understanding of how interface states affect device stability.展开更多
Although metal halide perovskites are increasingly popular for the next generation of efficient photovoltaic devices,the inevitable defects from the preparation process have become the notorious barrier to further imp...Although metal halide perovskites are increasingly popular for the next generation of efficient photovoltaic devices,the inevitable defects from the preparation process have become the notorious barrier to further improvement of performance,which increases non-radiative recombination and lowers the power conversion efficiency of solar cells.Surface passivation strategies have been affirmed as one of the most practical approaches to suppress these defects.Therefore,it is necessary to have a detailed review on the surface passivation to reveal the improvements of the devices.Herein,the mechanism and recent advances of surface passivation have been systematically summarized with respect to various passivation approaches,including the Lewis acid–base,the low-dimensional perovskite,inorganic molecules,and polymers.Finally,the review also offers the research trend and prospects of surface passivation.展开更多
The power conversion efficiency(PCE)of polymer solar cells(PSCs)has exceeded 19%due to the rapid progress of photoactive organic materials,including conjugated polymer donors and the matched non-fullerene acceptors(NF...The power conversion efficiency(PCE)of polymer solar cells(PSCs)has exceeded 19%due to the rapid progress of photoactive organic materials,including conjugated polymer donors and the matched non-fullerene acceptors(NFAs).Due to the high density of oxygen vacancies and the consequent photocatalytic reactivity of ZnO,structure inverted polymer solar cells with the ZnO electron transport layer(ETL)usually suffer poor device photostability.In this work,the eco-friendly glucose(Glu)is found to simultaneously improve the efficiency and stability of polymer:NFA solar cells.Under the optimal conditions,we achieved improved PCEs from 14.77%to 15.86%for the PM6:Y6 solar cells.Such a PCE improvement was attributed to the improvement in J_(SC) and FF,which is ascribed to the smoother and more hydrophobic surface of the ZnO/Glu surface,thereby enhancing the charge extraction efficiency and inhibiting charge recombination.Besides,UV-Vis absorption spectra analysis revealed that glucose modification could significantly inhibit the photodegradation of Y6,resulting in a significant improvement in the stability of the device with 92%of its initial PCE after aging for 1250 h.The application of natural interface materials in this work brings hope for the commercial application of organic solar cells and provides new ideas for developing new interface materials.展开更多
Lead free tin perovskite solar cells(PKSCs)are the most suitable alternative candidate for conventional lead perovskite solar cells.However,the efficiency and the stability are insufficient,mainly because of the poor ...Lead free tin perovskite solar cells(PKSCs)are the most suitable alternative candidate for conventional lead perovskite solar cells.However,the efficiency and the stability are insufficient,mainly because of the poor film quality and numerous defects.Here we introduce an efficient strategy based on a simple trimethylsilyl halide surface passivation to increase the film quality and reduce the defect density.At the same time,a hydrophobic protective layer on the perovskite surface is formed,which enhanced the PKSCs’stability.The efficiency of the solar cell after the passivation was enhanced from 10.05%to 12.22%with the improved open-circuit voltage from 0.57 V to 0.70 V.In addition,after 92 days of storage in N_(2) filled glovebox,the modified T-PKSCs demonstrated high stability maintaining 80%of its initial efficiency.This work provides a simple and widely used strategy to optimize the surface/interface optoelectronic properties of perovskites for giving more efficient and stable solar cells and other optoelectronic devices.展开更多
The electronic structures and optical properties of the [llO]-oriented Sil-xGex nanowires （NWs） passivated with different functional groups （-H, -F and-OH） are investigated by using first-principles calculations. ...The electronic structures and optical properties of the [llO]-oriented Sil-xGex nanowires （NWs） passivated with different functional groups （-H, -F and-OH） are investigated by using first-principles calculations. The results show that surface passivation influences the characteristics of electronic band structures significantly： the band gap widths and types （direct or indirect） of the Si1-xGe, NWs with different terminators show complex and robust variations, and the effective masses of the electrons in the NWs can be modulated dramatically by the terminators. The study of optical absorption shows that the main peaks of the parallel polarization component of Si1-x Gex NWs passivated with the functional groups exhibit prominent changes both in height and position, and are red-shifted with respect to those of corresponding pure Si NWs, indicating the importance of both the terminators and Ge concentrations. Our results demonstrate that the electronic and optical properties of Si1-xGex NWs can be tuned by utilizing selected functional groups as well as particular Ge concentrations for customizing purposes.展开更多
Solution-processed oxide semiconductors have been considered as a potential alternative to vacuum-based ones in printable electronics.However,despite spincoated InZnO(IZO)thin-film transistors(TFTs)have shown a relati...Solution-processed oxide semiconductors have been considered as a potential alternative to vacuum-based ones in printable electronics.However,despite spincoated InZnO(IZO)thin-film transistors(TFTs)have shown a relatively high mobil-ity,the lack of carrier suppressor and the high sensitivity to oxygen and water molecules in ambient air make them potentially suffer issues of poor stability.In this work,Al is used as the third cation doping element to study the effects on the electrical,optoelectronic,and physical properties of IZO TFTs.A hydrophobic self-assembled monolayer called octadecyltrimethoxysilane is introduced as the surface passivation layer,aiming to reduce the effects from air and understand the importance of top surface conditions in solution-processed,ultra-thin oxide TFTs.Owing to the reduced trap states within the film and at the top surface enabled by the doping and passivation,the optimized TFTs show an increased current on/off ratio,a reduced drain current hysteresis,and a significantly enhanced bias stress stability,compared with the untreated ones.By combining with high-capacitance AlO_(x),TFTs with a low operating voltage of 1.5 V,a current on/off ratio of>10^(4) and a mobility of 4.6 cm^(2)/(V·s)are demonstrated,suggesting the promising features for future low-cost,low-power electronics.展开更多
Due to the solution processable nature,the prepared perovskite films are polycrystalline with considerable number of defects.These defects,especially defects at interface accelerate the carrier recombination and reduc...Due to the solution processable nature,the prepared perovskite films are polycrystalline with considerable number of defects.These defects,especially defects at interface accelerate the carrier recombination and reduce the carrier collection.Besides,the surface defects also affect the long-term stability of the perovskite solar cells(PVSCs).To solve this problem,surface passivation molecules are introduced at selective interface(the interface between perovskite and carrier selective layer).This review summarizes recent progress of small molecules used in PVSCs.Firstly,different types of defect states in perovskite films are introduced and their effects on device performance are discussed.Subsequently,surface passivation molecules are divided into four categories,and the interaction between the functional groups of the surface passivation molecules and selective defect states in perovskite films are highlighted.Finally,we look into the prospects and challenges in design noble small molecules for PVSCs applications.展开更多
Atomic-layer-deposited（ALD） aluminum oxide（Al2O3） has demonstrated an excellent surface passivation for crystalline silicon（c-Si） surfaces, as well as for highly boron-doped c-Si surfaces. In this paper, water-b...Atomic-layer-deposited（ALD） aluminum oxide（Al2O3） has demonstrated an excellent surface passivation for crystalline silicon（c-Si） surfaces, as well as for highly boron-doped c-Si surfaces. In this paper, water-based thermal atomic layer deposition of Al2O3 films are fabricated for c-Si surface passivation. The influence of deposition conditions on the passivation quality is investigated. The results show that the excellent passivation on n-type c-Si can be achieved at a low thermal budget of 250℃ given a gas pressure of 0.15 Torr. The thickness-dependence of surface passivation indicates that the effective minority carrier lifetime increases drastically when the thickness of Al2O3 is larger than 10 nm. The influence of thermal post annealing treatments is also studied. Comparable carrier lifetime is achieved when Al2O3 sample is annealed for 15 min in forming gas in a temperature range from 400℃ to 450℃. In addition, the passivation quality can be further improved when a thin PECVD-SiNx cap layer is prepared on Al2O3, and an effective minority carrier lifetime of2.8 ms and implied Voc of 721 mV are obtained. In addition, several novel methods are proposed to restrain blistering.展开更多
Efficiency enhancement of Cs_(0.1)(CH_(3)NH_(3))_(0.9)PbI_(3) solar cell devices was performed by using iso-butyl ammonium iodide(IBA)passivated on Cs_(0.1)(CH_(3)NH_(3))_(0.9)PbI_(3) films.The n-i-p structure of pero...Efficiency enhancement of Cs_(0.1)(CH_(3)NH_(3))_(0.9)PbI_(3) solar cell devices was performed by using iso-butyl ammonium iodide(IBA)passivated on Cs_(0.1)(CH_(3)NH_(3))_(0.9)PbI_(3) films.The n-i-p structure of perovskite solar cell devices was fabricated with the structure of FTO/SnO_(2)/Cs_(0.1)(CH_(3)NH_(3))_(0.9)PbI_(3)(FTO,i.e.,fluorine doped tin oxide)and IBA/Spiro-OMeTAD/Ag.The effect of different weights of IBA passivated on Cs-doped perovskite solar cells(PSCs)was systematically investigated and compared with non-passivated devices.It was found that the 5-mg IBA-passivated devices exhibited a high power conversion efficiency(PCE)of 15.49%higher than 12.64%of non-IBA-passivated devices.The improvement of photovoltaic parameters of the 5-mg IBA-passivated device can be clearly observed compared to the Cs-doped device.The better performance of the IBA-passivated device can be confirmed by the reduction of PbI_(2) phase in the crystal structure,lower charge recombination rate,lower charge transfer resistance,and improved contact angle of perovskite films.Therefore,IBA passivation on Cs_(0.1)(CH_(3)NH)_(0.9)PbI_(3) is a promising technique to improve the efficiency of Cs-doped perovskite solar cells.展开更多
The surface passivation mechanism of nanocrystalline silicon powder was studied. The liquid nitrogen/argon was used as the medium to prepare the nanocrystalline silicon powder, using a cryomilling technology. The X-ra...The surface passivation mechanism of nanocrystalline silicon powder was studied. The liquid nitrogen/argon was used as the medium to prepare the nanocrystalline silicon powder, using a cryomilling technology. The X-ray diffraction, transmission electron microscopy, plasma emission spectroscopy and infrared spectrum were used to analyze the prepared samples, and density functional theory was used to investigate the cryomilling process. For nanocrystalline silicon powder cryomilled with liquid N2, the amorphous outer layer with N element is formed On the surface, and chemisorption caused by the formation of Si-N-Si bond leads to the surface passivation; although physisorpfion also he confirmed, the Si-N bond is steady after exploded in air for 30 days and no new bond is observed. For nanocrystalline silicon powder cryomilled with liquid At, no new chemical bond is Observed, Ar element absorbs on the surface of the prepared powder only through physisorption, and after exploded in air for 30 days, a Si-O bond can be observed obviously.展开更多
The degradation caused by surface states restricts the performance of near-surface semiconductor quantum dots(QDs).Here,we demonstrate optimized passivation techniques to improve the resonance fluorescence(RF)with dot...The degradation caused by surface states restricts the performance of near-surface semiconductor quantum dots(QDs).Here,we demonstrate optimized passivation techniques to improve the resonance fluorescence(RF)with dotto-dot comparisons.These optimized techniques,for the first time,reduce the linewidth and noise level of existing pulsed-RF signals,as well as revive pulsed-RF signals which originally are vanishing.The improvements are confirmed to originate from reduced surface state density and electric field after passivation,through optical and surface science characterizations.Our study promotes applications of the passivation techniques in thin-film quantum devices,paving the way for the further development of optimal QD-based quantum light sources.展开更多
Organic-inorganic hybrid metal halide perovskite solar cells(PSCs)have attracted much attention due to their high photoelectric conversion efficiency(PCE)and low cost.The certificated PCE of small active area(below 0....Organic-inorganic hybrid metal halide perovskite solar cells(PSCs)have attracted much attention due to their high photoelectric conversion efficiency(PCE)and low cost.The certificated PCE of small active area(below 0.1 cm^(2))device has reached 26.7%[1].However,when considering the scaled-up commercialization of PSCs,an obvious efficiency drop exists for the translation to large-area perovskite submodules(PSMs)with areas more than 200 cm^(2),thus limiting the practical commercialization[2].The major PCE gap between small area cells and large area modules arises the drop of open-circuit voltage(VOC)and fill factor(FF).Formamidinium lead iodide(FAPbI_(3))is now the mostly widely used and highly efficient perovskite composition.However,the photo-active black α-FAPbI_(3) phase will spontaneously transform into photo-inactive yellowδ-FAPbI_(3) phase at room temperature[3].展开更多
Bismuth vanadate(BiVO_(4))is a promising photoanode material for efficient photoelectrochemical(PEC)water splitting,whereas its performance is inhibited by detrimental surface states.To solve the problem,herein,a low-...Bismuth vanadate(BiVO_(4))is a promising photoanode material for efficient photoelectrochemical(PEC)water splitting,whereas its performance is inhibited by detrimental surface states.To solve the problem,herein,a low-cost organic molecule 1,3,5-benzenetricarboxylic acid(BTC)is selected for surface passivation of BiVO_(4) photoanodes(BVOs),which also provides bonding sites for Co^(2+)to anchor,resulting in a Co-BTC-BVO photoanode.Owing to its strong coordination with metal ions,BTC not only passivates surface states of BVO,but also provides bonding between BVO and catalytic active sites(Co^(2+))to form a molecular cocatalyst.Computational study and interfacial charge kinetic investigation reveal that chemical bonding formed at the interface greatly suppresses charge recombination and accelerates charge transfer.The obtained Co-BTC-BVO photoanode exhibits a photocurrent density of 4.82 mA/cm^(2) at 1.23 V vs.reversible hydrogen electrode(RHE)and a low onset potential of 0.22 VRHE under AM 1.5 G illumination,which ranks among the best photoanodes coupled with Co-based cocatalysts.This work presents a novel selection of passivation layers and emphasizes the significance of interfacial chemical bonding for the construction of efficient photoanodes.展开更多
Metal halide perovskites have demonstrated considerable promise across various optoelectronic applications.Surface passivation serves as a pivotal strategy to obtain high‐quality perovskite materials,either in a mann...Metal halide perovskites have demonstrated considerable promise across various optoelectronic applications.Surface passivation serves as a pivotal strategy to obtain high‐quality perovskite materials,either in a manner of bulk thin film or nanocrystal,with superior optoelectronic properties and stability.The current research focus in this regard primarily revolves around the use of organic molecules to passivate the surface of perovskites.However,organic passivation molecules always suffer from chemical instability and weak sec-ondary bonding modes,resulting in an unstable surface passivation motif.Inorganic materials,possessing more stable chemical structures and stronger chemical bonding than their organic counterparts,offer the opportunities to construct more robust passivation for the perovskite surfaces.Herein,in this review,we summarized and assessed recent advancements in inorganic sur-face passivation strategies for perovskite materials and devices,ranging from nanocrystals to bulk films.By discussing the mechanisms behind various inorganic passivation strategies,we aim to offer mechanistic insights and guidelines for future developments of more targeted surface passivation ap-proaches tailored for perovskite materials and devices.展开更多
Fast charge transfer and anti-photocorrosion are two crucial factors for developing efficient, durable photoanodes for photoelectrochemical （PEC） cells. Reduced graphene oxide （RGO） is a promising photoanode eleme...Fast charge transfer and anti-photocorrosion are two crucial factors for developing efficient, durable photoanodes for photoelectrochemical （PEC） cells. Reduced graphene oxide （RGO） is a promising photoanode element that can provide both of these. In this study, we elucidated the roles of RGO in the charge transfer and surface passivation of photoanodes by the precise design of a RGO-wrapped photoanode and examination of its PEC properties. Arrays of hetero-nanorods （HNRs） with three different designs were fabricated as photoanodes using RGO, CdSe nanoparticles （NPs）, and ZnO nanorods （NRs） as building blocks. CdSe@ZnO HNRs were prepared by decorating ZnO NRs with CdSe NPs. Finite-element analysis and experimental studies demonstrated that in the CdSe@ZnO HNRs, if only the ZnO NRs were wrapped by RGO, the conductivity between CdSe and ZnO was enhanced by RGO to shuttle charges. If RGO only surrounded the outside of the CdSe@ZnO HNRs, the corrosion was slowed owing to the passivation effect of RGO, which increased the electron lifetime of the photoanode. If both CdSe and ZnO were fully wrapped by RGO, the advantages of the two aforementioned cases were both obtained. RGO-wrapped CdSe@ZnO HNRs with position-controlled designs are promising photoanode materials with a high PEC efficiency, and the developed synthesis process can be applied to explore the design and fabrication of next-generation photoanodes using RGO as a buildin~ block.展开更多
In boron-doped p+-n crystalline silicon（Si） solar cells, p-type boron doping control and surface passivation play a vital role in the realization of high-efficiency and low cost pursuit. In this study, boron-doped p...In boron-doped p+-n crystalline silicon（Si） solar cells, p-type boron doping control and surface passivation play a vital role in the realization of high-efficiency and low cost pursuit. In this study, boron-doped p+-emitters are formed by boron diffusion in an open-tube furnace using borontribromide（BBr3） as precursor. The formed emitters are characterized in detail in terms of shape of the doping profile, surface doping concentration, junction depth, sheet resistance and removal of the boron-rich layer（BRL）. In the aspect of BRL removal, three different methods were adopted to investigate their influence on device performance. The results demonstrate that our proposed chemical etch treatment（CET） with the proper etching time could be an effective way to remove the BRL.After removal of the BRL, Al;O;/SiN;stacks are deposited by atomic layer deposition（ALD） and plasma-enhanced chemical vapor deposition（PECVD） to passivate the cell surface. It was found that a reasonably-high implied Voc of 680 mV has been achieved for the fabricated n-type Si solar cells.展开更多
The modification of the perovskite surface using functional additives is one of the most promising strategies to reduce nonradiative recombination and improve the stability of perovskite solar cells(PSCs).In this work...The modification of the perovskite surface using functional additives is one of the most promising strategies to reduce nonradiative recombination and improve the stability of perovskite solar cells(PSCs).In this work,a novel quaternary pyridinium-based halide salt,1-ethyl-4-(methoxycarbonyl)pyridinium iodide(EMCP-I),is introduced as an effective post-treatment molecule to improve the quality of the perovskite film.EMCP-I exhibits dual functionality to passivate both negatively and positively charged defects and improve the film morphology.Furthermore,the treatment fine-tunes energy level alignment between the perovskite layer and the hole transport layer(HTL),facilitating more efficient charge transport.Consequently,EMCP-I-treated devices achieve a remarkable power conversion efficiency(PCE)improvement from 20.5% to 22.6%,driven primarily by an enhanced open-circuit voltage(VOC).Beyond efficiency gains,the treatment significantly enhances the environmental and operational stabilities of solar cells.This work provides a guide for tailoring quaternary pyridinium-based molecules for simultaneous improvement of the efficiency and stability of PSCs.展开更多
CdSe nanoplatelets(NPLs)are promising candidates for on-chip light sources,yet their performance is hindered by surface defects and inefficient optical gain.Herein,we demonstrate that CdSeS crown passivation significa...CdSe nanoplatelets(NPLs)are promising candidates for on-chip light sources,yet their performance is hindered by surface defects and inefficient optical gain.Herein,we demonstrate that CdSeS crown passivation significantly enhances the photophysical property of CdSe NPLs.Laser spectroscopy techniques reveal suppressed electronic and hole trapping at lateral surfaces,leading to a 4.2-fold increase in photoluminescence quantum yield and a shortened emission lifetime from13.5 to 4.8 ns.In addition,amplified spontaneous emission is achieved under nanosecond pulse pumping,with thresholds of0.75 to 0.16 mJ/cm^(2)for CdSe and CdSe/CdSeS NPLs,respectively.By integrating CdSe/CdSeS NPLs with high-refractiveindex SiO2scatters,coherent random lasing is realized at a threshold of 0.21 mJ/cm^(2).These findings highlight the critical role of lateral surface passivation in optimizing optical gain and pave the way for low-cost,multifunctional nanophotonic devices.展开更多
Quaternary Ag-In-Ga-S(AIGS)quantum dot(QD)is considered a promising,spectral-tunable,and environmentally friendly luminescent display material.However,the more complex surface defect states of AIGS QDs resulting from ...Quaternary Ag-In-Ga-S(AIGS)quantum dot(QD)is considered a promising,spectral-tunable,and environmentally friendly luminescent display material.However,the more complex surface defect states of AIGS QDs resulting from the coexistence of multiple elements lead to a low(<60%)photoluminescence quantum yield(PLQY).Here,we develop a novel convenient method to introduce Z-type ligands ZnX_(2)(X=Cl,Br,I)for passivating the surface defects of AIGS QDs to dramatically enhance the PLQY and stability without affecting the crystalline structure and morphology.Results show that the addition of ZnCl_(2) during the purified process of AIGS QDs leads to a 3-fold increase of PLQY(from 28.5% to 87%).Impressively,the highest PLQY is up to a recorded value of 92%,which is comparable to typical heavy metal QDs.Exciton dynamics studies have shown that the rapid annihilation process of excitons in treated QDs is inhibited.We also confirm that the improvement in PLQY is a result of the effective passivation of the non-coordinating atom on the QD surface by building a new bonding between sulfur dangling and Zn2+.The realization of high PLQY will further promote the application of AIGS QDs in luminescent displays.展开更多
Two-dimensional(2D) alternating cation(ACI) perovskite surface defects,especially dominant iodine vacancies(V_Ⅰ) and undercoordinated Pb^(2+),limit the performance of perovskite solar cells(PVSCs).To address the issu...Two-dimensional(2D) alternating cation(ACI) perovskite surface defects,especially dominant iodine vacancies(V_Ⅰ) and undercoordinated Pb^(2+),limit the performance of perovskite solar cells(PVSCs).To address the issue,1-butyl-3-methylimidazolium trifluoro-methane-sulfonate(BMIMOTF) and its iodide counterpart(BMIMI) are utilized to modify the perovskite surface respectively.We find that BMIMI can change the perovskite surface,whereas BMIMOTF shows a nondestructive and more effective defect passivation,giving significantly reduced defect density and suppressed charge-carrier nonradiative recombination.This mainly attributes to the marked passivation efficacy of OTF-anion on V_Ⅰ and undercoordinated Pb^(2+),rather than BMIMI^(+) cation.Benefiting from the rational surface-modification of BMMIMOTF,the films exhibit an optimized energy level alignment,enhanced hydrophobicity and suppressed ion migration.Consequently,the BMIMOTF-modified devices achieve an impressive efficiency of 21.38% with a record open-circuit voltage of 1.195 V,which is among the best efficiencies reported for 2D PVSCs,and display greatly enhanced humidity and thermal stability.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.92265113,12034018,12474490,and 62404248)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0302300)。
文摘Strained germanium hole spin qubits are promising for quantum computing,but the devices hosting these qubits face challenges from high interface trap density,which originates from the naturally oxidized surface of the wafer.These traps can degrade the device stability and cause an excessively high threshold voltage.Surface passivation is regarded as an effective method to mitigate these impacts.In this study,we perform low-thermal-budget chemical passivation using the nitric acid oxidation of silicon method on the surface of strained germanium devices and investigate the impact of passivation on the device stability.The results demonstrate that surface passivation effectively reduces the interface defect density.This not only improves the stability of the device's threshold voltage but also enhances its long-term static stability.Furthermore,we construct a band diagram of hole surface tunneling at the static operating point to gain a deeper understanding of the physical mechanism through which passivation affects the device stability.This study provides valuable insights for future optimization of strained Ge-based quantum devices and advances our understanding of how interface states affect device stability.
基金The authors acknowledge the Science and Technology Development Fund,Macao SAR(File no.FDCT-0044/2020/A1,FDCT-091/2017/A2,FDCT-014/2017/AMJ,and FDCT-0163/2019/A3),UM’s research fund(File no.MYRG2018-00148-IAPME and SRG2019-00179-IAPME)the Natural Science Foundation of China(61935017,22022309,and 62105292),Natural Science Foundation of Guang-dong Province,China(2019A1515012186 and 2021A1515010024)+2 种基金Shenzhen-Hong Kong-Macao Science and Technology Innovation Project(Category C)(SGDX2020110309360100)Guangdong-Hong Kong-Macao Joint Labora-tory of Optoelectronic and Magnetic Functional Materials(2019B121205002)S.Mei thanks financial support from the Natural Science Foundation of China(62004231).
文摘Although metal halide perovskites are increasingly popular for the next generation of efficient photovoltaic devices,the inevitable defects from the preparation process have become the notorious barrier to further improvement of performance,which increases non-radiative recombination and lowers the power conversion efficiency of solar cells.Surface passivation strategies have been affirmed as one of the most practical approaches to suppress these defects.Therefore,it is necessary to have a detailed review on the surface passivation to reveal the improvements of the devices.Herein,the mechanism and recent advances of surface passivation have been systematically summarized with respect to various passivation approaches,including the Lewis acid–base,the low-dimensional perovskite,inorganic molecules,and polymers.Finally,the review also offers the research trend and prospects of surface passivation.
基金financially supported by the National Natural Science Foundation of China (No.22075315)the Chinese Academy of Science (Nos.YJKYYQ20180029 and GJHZ2092-019)the Youth Innovation Promotion Association,CAS (No.2019317)。
文摘The power conversion efficiency(PCE)of polymer solar cells(PSCs)has exceeded 19%due to the rapid progress of photoactive organic materials,including conjugated polymer donors and the matched non-fullerene acceptors(NFAs).Due to the high density of oxygen vacancies and the consequent photocatalytic reactivity of ZnO,structure inverted polymer solar cells with the ZnO electron transport layer(ETL)usually suffer poor device photostability.In this work,the eco-friendly glucose(Glu)is found to simultaneously improve the efficiency and stability of polymer:NFA solar cells.Under the optimal conditions,we achieved improved PCEs from 14.77%to 15.86%for the PM6:Y6 solar cells.Such a PCE improvement was attributed to the improvement in J_(SC) and FF,which is ascribed to the smoother and more hydrophobic surface of the ZnO/Glu surface,thereby enhancing the charge extraction efficiency and inhibiting charge recombination.Besides,UV-Vis absorption spectra analysis revealed that glucose modification could significantly inhibit the photodegradation of Y6,resulting in a significant improvement in the stability of the device with 92%of its initial PCE after aging for 1250 h.The application of natural interface materials in this work brings hope for the commercial application of organic solar cells and provides new ideas for developing new interface materials.
文摘Lead free tin perovskite solar cells(PKSCs)are the most suitable alternative candidate for conventional lead perovskite solar cells.However,the efficiency and the stability are insufficient,mainly because of the poor film quality and numerous defects.Here we introduce an efficient strategy based on a simple trimethylsilyl halide surface passivation to increase the film quality and reduce the defect density.At the same time,a hydrophobic protective layer on the perovskite surface is formed,which enhanced the PKSCs’stability.The efficiency of the solar cell after the passivation was enhanced from 10.05%to 12.22%with the improved open-circuit voltage from 0.57 V to 0.70 V.In addition,after 92 days of storage in N_(2) filled glovebox,the modified T-PKSCs demonstrated high stability maintaining 80%of its initial efficiency.This work provides a simple and widely used strategy to optimize the surface/interface optoelectronic properties of perovskites for giving more efficient and stable solar cells and other optoelectronic devices.
基金Supported by the National Natural Science Foundation of China under Grant No 11004142the Program for New Century Excellent Talents in University under Grant No 11-035the Project Sponsored by the Scientific Research Foundation for ROCS of the Ministry of Education of China
文摘The electronic structures and optical properties of the [llO]-oriented Sil-xGex nanowires （NWs） passivated with different functional groups （-H, -F and-OH） are investigated by using first-principles calculations. The results show that surface passivation influences the characteristics of electronic band structures significantly： the band gap widths and types （direct or indirect） of the Si1-xGe, NWs with different terminators show complex and robust variations, and the effective masses of the electrons in the NWs can be modulated dramatically by the terminators. The study of optical absorption shows that the main peaks of the parallel polarization component of Si1-x Gex NWs passivated with the functional groups exhibit prominent changes both in height and position, and are red-shifted with respect to those of corresponding pure Si NWs, indicating the importance of both the terminators and Ge concentrations. Our results demonstrate that the electronic and optical properties of Si1-xGex NWs can be tuned by utilizing selected functional groups as well as particular Ge concentrations for customizing purposes.
文摘Solution-processed oxide semiconductors have been considered as a potential alternative to vacuum-based ones in printable electronics.However,despite spincoated InZnO(IZO)thin-film transistors(TFTs)have shown a relatively high mobil-ity,the lack of carrier suppressor and the high sensitivity to oxygen and water molecules in ambient air make them potentially suffer issues of poor stability.In this work,Al is used as the third cation doping element to study the effects on the electrical,optoelectronic,and physical properties of IZO TFTs.A hydrophobic self-assembled monolayer called octadecyltrimethoxysilane is introduced as the surface passivation layer,aiming to reduce the effects from air and understand the importance of top surface conditions in solution-processed,ultra-thin oxide TFTs.Owing to the reduced trap states within the film and at the top surface enabled by the doping and passivation,the optimized TFTs show an increased current on/off ratio,a reduced drain current hysteresis,and a significantly enhanced bias stress stability,compared with the untreated ones.By combining with high-capacitance AlO_(x),TFTs with a low operating voltage of 1.5 V,a current on/off ratio of>10^(4) and a mobility of 4.6 cm^(2)/(V·s)are demonstrated,suggesting the promising features for future low-cost,low-power electronics.
基金support from Key Program of National Natural Science Foundation of China(22133006)the National Natural Science Foundation of China(ZX20210286)+1 种基金the Fundamental Research Funds for the Central Universities(20CX06004A)Talent Introduction Program of China University of Petroleum(East China)(ZX20190162)and the Post-Graduate Innovation Project of China University of Petroluem(East China)(YCX2021140)are acknowledged.We also thank the support from the Yankuang Group 2019 Science and Technology Program(YKKJ2019AJ05JG-R60).Prof.X.Li and Dr.T.Zhang thank the Taishan Scholar Programof Shandong Province(ts201712019,tsnq201909069)for financial support.
文摘Due to the solution processable nature,the prepared perovskite films are polycrystalline with considerable number of defects.These defects,especially defects at interface accelerate the carrier recombination and reduce the carrier collection.Besides,the surface defects also affect the long-term stability of the perovskite solar cells(PVSCs).To solve this problem,surface passivation molecules are introduced at selective interface(the interface between perovskite and carrier selective layer).This review summarizes recent progress of small molecules used in PVSCs.Firstly,different types of defect states in perovskite films are introduced and their effects on device performance are discussed.Subsequently,surface passivation molecules are divided into four categories,and the interaction between the functional groups of the surface passivation molecules and selective defect states in perovskite films are highlighted.Finally,we look into the prospects and challenges in design noble small molecules for PVSCs applications.
基金Project supported by the Beijing Municipal Science and Technology Commission,China(Grant No.Z151100003515003)the National Natural Science Foundation of China(Grant Nos.110751402347,61274134,51402064,61274059,and 51602340)+3 种基金the University of Science and Technology Beijing(USTB)Start-up Program,China(Grant No.06105033)the Beijing Municipal Innovation and Research Base,China(Grant No.Z161100005016095)the Fundamental Research Funds for the Central Universities,China(Grant Nos.FRF-UM-15-032 and 06400071)the Youth Innovation Promotion Association of Chinese Academy of Sciences(Grant No.2015387)
文摘Atomic-layer-deposited（ALD） aluminum oxide（Al2O3） has demonstrated an excellent surface passivation for crystalline silicon（c-Si） surfaces, as well as for highly boron-doped c-Si surfaces. In this paper, water-based thermal atomic layer deposition of Al2O3 films are fabricated for c-Si surface passivation. The influence of deposition conditions on the passivation quality is investigated. The results show that the excellent passivation on n-type c-Si can be achieved at a low thermal budget of 250℃ given a gas pressure of 0.15 Torr. The thickness-dependence of surface passivation indicates that the effective minority carrier lifetime increases drastically when the thickness of Al2O3 is larger than 10 nm. The influence of thermal post annealing treatments is also studied. Comparable carrier lifetime is achieved when Al2O3 sample is annealed for 15 min in forming gas in a temperature range from 400℃ to 450℃. In addition, the passivation quality can be further improved when a thin PECVD-SiNx cap layer is prepared on Al2O3, and an effective minority carrier lifetime of2.8 ms and implied Voc of 721 mV are obtained. In addition, several novel methods are proposed to restrain blistering.
基金financial support from the Development and Promotion of Science and Technology Talent Project(DPST) and Graduate School,Chiang Mai University
文摘Efficiency enhancement of Cs_(0.1)(CH_(3)NH_(3))_(0.9)PbI_(3) solar cell devices was performed by using iso-butyl ammonium iodide(IBA)passivated on Cs_(0.1)(CH_(3)NH_(3))_(0.9)PbI_(3) films.The n-i-p structure of perovskite solar cell devices was fabricated with the structure of FTO/SnO_(2)/Cs_(0.1)(CH_(3)NH_(3))_(0.9)PbI_(3)(FTO,i.e.,fluorine doped tin oxide)and IBA/Spiro-OMeTAD/Ag.The effect of different weights of IBA passivated on Cs-doped perovskite solar cells(PSCs)was systematically investigated and compared with non-passivated devices.It was found that the 5-mg IBA-passivated devices exhibited a high power conversion efficiency(PCE)of 15.49%higher than 12.64%of non-IBA-passivated devices.The improvement of photovoltaic parameters of the 5-mg IBA-passivated device can be clearly observed compared to the Cs-doped device.The better performance of the IBA-passivated device can be confirmed by the reduction of PbI_(2) phase in the crystal structure,lower charge recombination rate,lower charge transfer resistance,and improved contact angle of perovskite films.Therefore,IBA passivation on Cs_(0.1)(CH_(3)NH)_(0.9)PbI_(3) is a promising technique to improve the efficiency of Cs-doped perovskite solar cells.
基金Supported by the National Natural Science Foundation of China(No.51202171)the Specialized Research Fund for the Doctoral Program of Higher Education of China(No.20120143120004)the"111"Project(No.B13035)
文摘The surface passivation mechanism of nanocrystalline silicon powder was studied. The liquid nitrogen/argon was used as the medium to prepare the nanocrystalline silicon powder, using a cryomilling technology. The X-ray diffraction, transmission electron microscopy, plasma emission spectroscopy and infrared spectrum were used to analyze the prepared samples, and density functional theory was used to investigate the cryomilling process. For nanocrystalline silicon powder cryomilled with liquid N2, the amorphous outer layer with N element is formed On the surface, and chemisorption caused by the formation of Si-N-Si bond leads to the surface passivation; although physisorpfion also he confirmed, the Si-N bond is steady after exploded in air for 30 days and no new bond is observed. For nanocrystalline silicon powder cryomilled with liquid At, no new chemical bond is Observed, Ar element absorbs on the surface of the prepared powder only through physisorption, and after exploded in air for 30 days, a Si-O bond can be observed obviously.
基金supported by the National Natural Science Foundation of China(62474168 and 12012422)the Chinese Academy of Sciences Project for Young Scientists in Basic Research(YSBR-112)+2 种基金the National Key R&D Program of China(2019YFA0308700)the Chinese Academy of Sciences,the Anhui Initiative in Quantum Information Technologies,the Shanghai Municipal Science and Technology Major Project(2019SHZDZX01)the Innovation Program for Quantum Science and Technology(2021ZD0300204 and 2021ZD0301400).
文摘The degradation caused by surface states restricts the performance of near-surface semiconductor quantum dots(QDs).Here,we demonstrate optimized passivation techniques to improve the resonance fluorescence(RF)with dotto-dot comparisons.These optimized techniques,for the first time,reduce the linewidth and noise level of existing pulsed-RF signals,as well as revive pulsed-RF signals which originally are vanishing.The improvements are confirmed to originate from reduced surface state density and electric field after passivation,through optical and surface science characterizations.Our study promotes applications of the passivation techniques in thin-film quantum devices,paving the way for the further development of optimal QD-based quantum light sources.
基金support from open fund of Fujian Provincial Key Laboratory of Functional Materials and Applications(Xiamen University of Technology,fma2024003)the National Key R&D Program of China(No.2021YFB3500400)the National Natural Science Foundation of China(Nos.52073286 and 22275185).
文摘Organic-inorganic hybrid metal halide perovskite solar cells(PSCs)have attracted much attention due to their high photoelectric conversion efficiency(PCE)and low cost.The certificated PCE of small active area(below 0.1 cm^(2))device has reached 26.7%[1].However,when considering the scaled-up commercialization of PSCs,an obvious efficiency drop exists for the translation to large-area perovskite submodules(PSMs)with areas more than 200 cm^(2),thus limiting the practical commercialization[2].The major PCE gap between small area cells and large area modules arises the drop of open-circuit voltage(VOC)and fill factor(FF).Formamidinium lead iodide(FAPbI_(3))is now the mostly widely used and highly efficient perovskite composition.However,the photo-active black α-FAPbI_(3) phase will spontaneously transform into photo-inactive yellowδ-FAPbI_(3) phase at room temperature[3].
基金support from the National Natural Science Foundation of China(No.51672173,U1733130)Shanghai Science and Technology Committee(Nos.21ZR1435700,18520744700, 18JC1410500)Shanghai Jiao Tong University Medical Engineering Cross Research Program(No.YG2023ZD18).
文摘Bismuth vanadate(BiVO_(4))is a promising photoanode material for efficient photoelectrochemical(PEC)water splitting,whereas its performance is inhibited by detrimental surface states.To solve the problem,herein,a low-cost organic molecule 1,3,5-benzenetricarboxylic acid(BTC)is selected for surface passivation of BiVO_(4) photoanodes(BVOs),which also provides bonding sites for Co^(2+)to anchor,resulting in a Co-BTC-BVO photoanode.Owing to its strong coordination with metal ions,BTC not only passivates surface states of BVO,but also provides bonding between BVO and catalytic active sites(Co^(2+))to form a molecular cocatalyst.Computational study and interfacial charge kinetic investigation reveal that chemical bonding formed at the interface greatly suppresses charge recombination and accelerates charge transfer.The obtained Co-BTC-BVO photoanode exhibits a photocurrent density of 4.82 mA/cm^(2) at 1.23 V vs.reversible hydrogen electrode(RHE)and a low onset potential of 0.22 VRHE under AM 1.5 G illumination,which ranks among the best photoanodes coupled with Co-based cocatalysts.This work presents a novel selection of passivation layers and emphasizes the significance of interfacial chemical bonding for the construction of efficient photoanodes.
基金National Natural Science Foundation of China,Grant/Award Number:62274146Natural Science Foundation of Zhejiang Province of China,Grant/Award Numbers:LD22E020002,LD24E020001,LR24F040001+1 种基金Key R&D Program of Zhejiang,Grant/Award Number:2024SSYS0061Shanxi‐Zheda Institute of Advanced Materials and Chemical Engineering,Grant/Award Number:2021SZ‐FR006。
文摘Metal halide perovskites have demonstrated considerable promise across various optoelectronic applications.Surface passivation serves as a pivotal strategy to obtain high‐quality perovskite materials,either in a manner of bulk thin film or nanocrystal,with superior optoelectronic properties and stability.The current research focus in this regard primarily revolves around the use of organic molecules to passivate the surface of perovskites.However,organic passivation molecules always suffer from chemical instability and weak sec-ondary bonding modes,resulting in an unstable surface passivation motif.Inorganic materials,possessing more stable chemical structures and stronger chemical bonding than their organic counterparts,offer the opportunities to construct more robust passivation for the perovskite surfaces.Herein,in this review,we summarized and assessed recent advancements in inorganic sur-face passivation strategies for perovskite materials and devices,ranging from nanocrystals to bulk films.By discussing the mechanisms behind various inorganic passivation strategies,we aim to offer mechanistic insights and guidelines for future developments of more targeted surface passivation ap-proaches tailored for perovskite materials and devices.
文摘Fast charge transfer and anti-photocorrosion are two crucial factors for developing efficient, durable photoanodes for photoelectrochemical （PEC） cells. Reduced graphene oxide （RGO） is a promising photoanode element that can provide both of these. In this study, we elucidated the roles of RGO in the charge transfer and surface passivation of photoanodes by the precise design of a RGO-wrapped photoanode and examination of its PEC properties. Arrays of hetero-nanorods （HNRs） with three different designs were fabricated as photoanodes using RGO, CdSe nanoparticles （NPs）, and ZnO nanorods （NRs） as building blocks. CdSe@ZnO HNRs were prepared by decorating ZnO NRs with CdSe NPs. Finite-element analysis and experimental studies demonstrated that in the CdSe@ZnO HNRs, if only the ZnO NRs were wrapped by RGO, the conductivity between CdSe and ZnO was enhanced by RGO to shuttle charges. If RGO only surrounded the outside of the CdSe@ZnO HNRs, the corrosion was slowed owing to the passivation effect of RGO, which increased the electron lifetime of the photoanode. If both CdSe and ZnO were fully wrapped by RGO, the advantages of the two aforementioned cases were both obtained. RGO-wrapped CdSe@ZnO HNRs with position-controlled designs are promising photoanode materials with a high PEC efficiency, and the developed synthesis process can be applied to explore the design and fabrication of next-generation photoanodes using RGO as a buildin~ block.
基金Project supported by the Beijing Municipal Science and Technology Commission,China(No.Z151100003515003)the Beijing Natural Science Foundation(No.4173077,2184112)+3 种基金the Fundamental Research Funds for the Central Universities,China(Nos.FRF-BR-16-018A,FRF-TP-17-022A1,06400071)the National Natural Science Foundation of China(Nos.110751402347,61274134,51402064,61274059,51602340)the Beijing Municipal Innovation and Research Base,China(No.Z161100005016095)the Youth Innovation Promotion Association of Chinese Academy of Sciences(No.2015387)
文摘In boron-doped p+-n crystalline silicon（Si） solar cells, p-type boron doping control and surface passivation play a vital role in the realization of high-efficiency and low cost pursuit. In this study, boron-doped p+-emitters are formed by boron diffusion in an open-tube furnace using borontribromide（BBr3） as precursor. The formed emitters are characterized in detail in terms of shape of the doping profile, surface doping concentration, junction depth, sheet resistance and removal of the boron-rich layer（BRL）. In the aspect of BRL removal, three different methods were adopted to investigate their influence on device performance. The results demonstrate that our proposed chemical etch treatment（CET） with the proper etching time could be an effective way to remove the BRL.After removal of the BRL, Al;O;/SiN;stacks are deposited by atomic layer deposition（ALD） and plasma-enhanced chemical vapor deposition（PECVD） to passivate the cell surface. It was found that a reasonably-high implied Voc of 680 mV has been achieved for the fabricated n-type Si solar cells.
基金financially supported by The Scientific and Technological Research Council of Türkiye(TüBITAK)under Project No.119F185the support of the Interdisciplinary Centre for Mathematical and Computational Modelling at the University of Warsaw(ICM UW)under computational allocation no.g93-1617。
文摘The modification of the perovskite surface using functional additives is one of the most promising strategies to reduce nonradiative recombination and improve the stability of perovskite solar cells(PSCs).In this work,a novel quaternary pyridinium-based halide salt,1-ethyl-4-(methoxycarbonyl)pyridinium iodide(EMCP-I),is introduced as an effective post-treatment molecule to improve the quality of the perovskite film.EMCP-I exhibits dual functionality to passivate both negatively and positively charged defects and improve the film morphology.Furthermore,the treatment fine-tunes energy level alignment between the perovskite layer and the hole transport layer(HTL),facilitating more efficient charge transport.Consequently,EMCP-I-treated devices achieve a remarkable power conversion efficiency(PCE)improvement from 20.5% to 22.6%,driven primarily by an enhanced open-circuit voltage(VOC).Beyond efficiency gains,the treatment significantly enhances the environmental and operational stabilities of solar cells.This work provides a guide for tailoring quaternary pyridinium-based molecules for simultaneous improvement of the efficiency and stability of PSCs.
基金supported by the National Natural Science Foundation of China(Grant No.62174079)Guangdong Provincial Quantum Science Strategic Initiative(Grant No.GDZX2404006)Science,Technology and Innovation Commission of Shenzhen Municipality(Grant No.JCYJ20220530113015035)。
文摘CdSe nanoplatelets(NPLs)are promising candidates for on-chip light sources,yet their performance is hindered by surface defects and inefficient optical gain.Herein,we demonstrate that CdSeS crown passivation significantly enhances the photophysical property of CdSe NPLs.Laser spectroscopy techniques reveal suppressed electronic and hole trapping at lateral surfaces,leading to a 4.2-fold increase in photoluminescence quantum yield and a shortened emission lifetime from13.5 to 4.8 ns.In addition,amplified spontaneous emission is achieved under nanosecond pulse pumping,with thresholds of0.75 to 0.16 mJ/cm^(2)for CdSe and CdSe/CdSeS NPLs,respectively.By integrating CdSe/CdSeS NPLs with high-refractiveindex SiO2scatters,coherent random lasing is realized at a threshold of 0.21 mJ/cm^(2).These findings highlight the critical role of lateral surface passivation in optimizing optical gain and pave the way for low-cost,multifunctional nanophotonic devices.
基金supported by the National Natural Science Foundation of China(Nos.62374089,61904081 and 51672132)the Natural Science Foundation of Jiangsu Province(No.BK20190449)+1 种基金the Postdoctoral Research Funding Program of Jiangsu Province(No.2020Z144)the Fundamental Research Funds for the Central Universities(No.30923010928).
文摘Quaternary Ag-In-Ga-S(AIGS)quantum dot(QD)is considered a promising,spectral-tunable,and environmentally friendly luminescent display material.However,the more complex surface defect states of AIGS QDs resulting from the coexistence of multiple elements lead to a low(<60%)photoluminescence quantum yield(PLQY).Here,we develop a novel convenient method to introduce Z-type ligands ZnX_(2)(X=Cl,Br,I)for passivating the surface defects of AIGS QDs to dramatically enhance the PLQY and stability without affecting the crystalline structure and morphology.Results show that the addition of ZnCl_(2) during the purified process of AIGS QDs leads to a 3-fold increase of PLQY(from 28.5% to 87%).Impressively,the highest PLQY is up to a recorded value of 92%,which is comparable to typical heavy metal QDs.Exciton dynamics studies have shown that the rapid annihilation process of excitons in treated QDs is inhibited.We also confirm that the improvement in PLQY is a result of the effective passivation of the non-coordinating atom on the QD surface by building a new bonding between sulfur dangling and Zn2+.The realization of high PLQY will further promote the application of AIGS QDs in luminescent displays.
基金financially supported by the National Natural Science Foundation of China (62174021 and 62104028)the Creative Research Groups of the National Natural Science Foundation of Sichuan Province (2023NSFSC1973)+7 种基金the Sichuan Science and Technology Program (MZGC20230008)the Natural Science Foundation of Sichuan Province (2022NSFSC0899)the China Postdoctoral Science Foundation (2021M700689)the Grant SCITLAB (20012) of Intelligent Terminal Key Laboratory of Sichuan ProvinceFundamental Research Funds for the Central Universities (ZYGX2019J054)the Guangdong Basic and Applied Basic Research Foundation (2019A1515110438)sponsored by the University of Kentuckythe Sichuan Province Key Laboratory of Display Science and Technology。
文摘Two-dimensional(2D) alternating cation(ACI) perovskite surface defects,especially dominant iodine vacancies(V_Ⅰ) and undercoordinated Pb^(2+),limit the performance of perovskite solar cells(PVSCs).To address the issue,1-butyl-3-methylimidazolium trifluoro-methane-sulfonate(BMIMOTF) and its iodide counterpart(BMIMI) are utilized to modify the perovskite surface respectively.We find that BMIMI can change the perovskite surface,whereas BMIMOTF shows a nondestructive and more effective defect passivation,giving significantly reduced defect density and suppressed charge-carrier nonradiative recombination.This mainly attributes to the marked passivation efficacy of OTF-anion on V_Ⅰ and undercoordinated Pb^(2+),rather than BMIMI^(+) cation.Benefiting from the rational surface-modification of BMMIMOTF,the films exhibit an optimized energy level alignment,enhanced hydrophobicity and suppressed ion migration.Consequently,the BMIMOTF-modified devices achieve an impressive efficiency of 21.38% with a record open-circuit voltage of 1.195 V,which is among the best efficiencies reported for 2D PVSCs,and display greatly enhanced humidity and thermal stability.
