Efficient photocatalytic water splitting can be significantly enhanced through the careful design of S-scheme heterostructures,which play a pivotal role in optimizing performance.Herein,we report the construction of Z...Efficient photocatalytic water splitting can be significantly enhanced through the careful design of S-scheme heterostructures,which play a pivotal role in optimizing performance.Herein,we report the construction of ZnIn_(2)S_(4)/CdS S-scheme heterojunctions under ambient conditions,based on a sonochemical strategy.This structure is facilitated by the well-matched interface between the(007)plane of layered ZnIn_(2)S_(4)and the(101)plane of CdS,leading to a threshold optical response of 2.12 eV,which optimally aligns with visible light absorption.As a proof of concept,the resulting ZnIn_(2)S_(4)/CdS catalysts demonstrate a remarkable improvement in photocatalytic H_(2) evolution,achieving a rate of 5678.2μmol h^(-1)g^(-1)under visible light irradiation(λ>400 nm).This rate is approximately 10 times higher than that of pristine ZnIn_(2)S_(4)nanosheets(NSs)and about 4.6 times higher than that of CdS nanoparticles(NPs),surpassing the performance of most ZnIn_(2)S_(4)-based photocatalysts reported to date.Moreover,they deliver a robust photocatalytic performance during long-term operation of up to 60 h,showing their potential for use in practical applications.Based on the theoretical calculation and experimental results,it is verified that the movements of electrons and holes in the opposite direction could be induced by the disparity in the work function and the internal electric field within the interfaces,thus facilitating the construction of S-scheme heterojunctions,which fundamentally suppresses carrier recombination while minimizing photocorrosion of ZnIn_(2)S_(4)toward enhanced photocatalytic behaviors.展开更多
This scientific paper presents a study investigating the effects of defects at the CdS/CIGS and CdS/SDL interfaces on the performance of CIGS solar cells. The objective of this study is to analyze the influence of def...This scientific paper presents a study investigating the effects of defects at the CdS/CIGS and CdS/SDL interfaces on the performance of CIGS solar cells. The objective of this study is to analyze the influence of defects at the interface between the CdS buffer layer and the CIGS absorber, as well as the surface defect layer (SDL), on CIGS solar cell performance. The study explores three key aspects: the impact of the conduction band offset (CBO) at the CdS/CIGS interface, the effects of interface defects and defect density on performance, and the combined influence of CBO and defect density at the CdS/ SDL and SDL/CIGS interfaces. For interface defects not exceeding 10<sup>13</sup> cm<sup>-2</sup>, we obtained a good efficiency of 22.9% when -0.1 eV analyzing the quality of CdS/SDL and SDL/CIGS junctions, it appears that defects at the SDL/CIGS interface have very little impact on the performances of the CIGS solar cell. By optimizing the electrical parameters of the CdS/SDL interface defects, we achieved a conversion efficiency of 23.1% when -0.05 eV < CBO < 0.05 eV.展开更多
Using first-principles calculations within density functional theory, we study the atomic structures and electronic properties of the perfect and defective （2VCu＋ Incu） CulnGaSe2/CdS interfaces theoretically, espec...Using first-principles calculations within density functional theory, we study the atomic structures and electronic properties of the perfect and defective （2VCu＋ Incu） CulnGaSe2/CdS interfaces theoretically, especially the interface states. We find that the local lattice structure of （2VCu＋ InCu） interface is somewhat disorganized. By analyzing the local density of states projected on several atomic layers of the two interfaces models, we find that for the （2VCu＋InCu） interface the interface states near the Fermi level in CulnGaSe2 and CdS band gap regions are mainly composed of interracial Se-4p, Cu-3d and S-3p orbitals, while for the perfect interface there are no clear interface states in the CulnGaSe2 region but only some interface states which are mainly composed of S-3p orbitals in the valance band of CdS region.展开更多
Flexible Cu2ZnSn(S,Se)4(CZTSSe)solar cells show great potential applications due to low-cost,nontoxicity,and stability.The device performances under an especial open circuit voltage(VOC)are limited by the defect recom...Flexible Cu2ZnSn(S,Se)4(CZTSSe)solar cells show great potential applications due to low-cost,nontoxicity,and stability.The device performances under an especial open circuit voltage(VOC)are limited by the defect recombination of CZTSSe/CdS heterojunction interface.We improve the deposition technique to obtain compact CdS layers without any pinholes for flexible CZTSSe solar cells on Mo foils.The efficiency of the device is improved from 5.7%to 6.86%by highquality junction interface.Furthermore,aiming at the S loss of CdS film,the S source concentration in deposition process is investigated to passivate the defects and improve the CdS film quality.The flexible Mo-foil-based CZTSSe solar cells are obtained to possess a 9.05%efficiency with a VOC of 0.44 V at an optimized S source concentration of 0.68 mol/L.Systematic physical measurements indicate that the S source control can effectively suppress the interface recombination and reduce the VOCdeficit.For the CZTSSe device bending characteristics,the device efficiency is almost constant after1000 bends,manifesting that the CZTSSe device has an excellent mechanical flexibility.The effective improvement strategy of CdS deposition is expected to provide a new perspective for promoting the conversion efficiency of CZTSSe solar cells.展开更多
Interface engineering can improve the charge separation efficiency and inhibit photocorrosion is an emerging direction of developing more efficient and cost-effective photocatalytic systems.Herein,we report the sulfur...Interface engineering can improve the charge separation efficiency and inhibit photocorrosion is an emerging direction of developing more efficient and cost-effective photocatalytic systems.Herein,we report the sulfur-confined intimate Cd S intergrown Cd(Cd S/Cd)Ohmic junction(peanut-chocolate-ball like)for high-efficient H2production with superior anti-photocorrosion ability,which was fabricated from in-situ photoreduction of CdS intergrown Cd2SO4(OH)2(CdS/Cd2SO4(OH)2)prepared through a facile space-controlled-solvothermal method.The ratios of CdS/Cd can be effectively controlled by tunning that of CdS/Cd2SO4(OH)2which were prepared by adjusting the volume of reaction liquid and the remaining space of the reactor.Experiments investigations and density functional theory(DFT)calculations reveal that the Cd S intergrown Cd Ohmic junction interfaces(with appropriate content Cd intergrown on Cd S(19.54 wt%))are beneficial in facilitating the transfer of photogenerated electrons by constructing an interfacial electric field and forming sulfur-confined structures for preventing the positive holes(h+)oxidize the Cd S.This contributes to a high photocatalytic H2production activity of 95.40μmol h-1(about 32.3 times higher than bare Cd S)and possesses outstanding photocatalytic stability over 205 h,much longer than most Cd S-based photocatalysts previously reported.The interface engineering design inspired by the structure of peanut-chocolate-ball can greatly promote the future development of catalytic systems for wider application.展开更多
The electron transport behavior across the interface plays an important role in determining the performance of op- toelectronic devices based on heterojunctions. Here through growing CdS thin film on silicon nanoporou...The electron transport behavior across the interface plays an important role in determining the performance of op- toelectronic devices based on heterojunctions. Here through growing CdS thin film on silicon nanoporous pillar array, an untraditional, nonplanar, and multi-interface CdS/Si nanoheterojunction is prepared. The current density versus voltage curve is measured and an obvious rectification effect is observed. Based on the fitting results and model analyses on the forward and reverse conduction characteristics, the electron transport mechanism under low forward bias, high forward bias, and reverse bias are attributed to the Ohmic regime, space-charge-limited current regime, and modified Poole-Frenkel regime respectively. The forward and reverse electrical behaviors are found to be highly related to the distribution of inter- facial trap states and the existence of localized electric field respectively. These results might be helpful for optimizing the preparing procedures to realize high-performance silicon-based CdS optoelectronic devices.展开更多
Improved hybrid solar cells consisting of vertical aligned cadmium sulfide （CdS） nanorod arrays and interpenetrating polythiophene （P3HT） have been achieved via modification of CdS nanorod surface by using conjuga...Improved hybrid solar cells consisting of vertical aligned cadmium sulfide （CdS） nanorod arrays and interpenetrating polythiophene （P3HT） have been achieved via modification of CdS nanorod surface by using conjugated N719 dye. The complete infiltration of P3HT between CdS nanorods interspacing was verified by scanning electron microscopy. By employing absorption and photoluminescence spectra, and current-voltage characterization the interaction between N719 molecules and CdS nanorods/P3HT interface was explored, and the role of N719 dye on the improvement of device performance was discussed.展开更多
Highly crystalline and transparent CdS films are grown by utilizing the vacuum thermal evaporation （VTE） method. The structural, surface morphological, and optical properties of the films are studied and compared wi...Highly crystalline and transparent CdS films are grown by utilizing the vacuum thermal evaporation （VTE） method. The structural, surface morphological, and optical properties of the films are studied and compared with those prepared by chemical bath deposition （CBD）. It is found that the films deposited at a high substrate temperature （200 ℃） have a preferential orientation along （002） which is consistent with CBD-grown films. Absorption spectra reveal that the films are highly transparent and the optical band gap values are found to be in a range of 2.44 eV-2.56 eV. Culnl_xGaxSe2 （CIGS） solar cells with in-situ VTE-grown CdS films exhibit higher values of Voc together with smaller values of Jsc than those from CBD. Eventually the conversion efficiency and fill factor become slightly better than those from the CBD method. Our work suggests that the in-situ thermal evaporation method can be a competitive alternative to the CBD method, particularly in the physical- and vacuum-based CIGS technology.展开更多
In this paper, a comparative study of the maximum power on the shading rate on the maximum power of thin film PV modules. Thus two thin film PV modules of type Copper indium gallium selenide, CIGS, of 90W power and a ...In this paper, a comparative study of the maximum power on the shading rate on the maximum power of thin film PV modules. Thus two thin film PV modules of type Copper indium gallium selenide, CIGS, of 90W power and a CdTe (Cadmium telluride)/CdS (Cadmium sulfide) module, of maximum power 75 W. These modules, reference SN-CIGS90 and CX3 75 were tested under the conditions of the installation site to ensure their proper functioning and to determine the initial values of electrical parameters before shading. The results obtained are as follows: for the CIGS: Pm (80.717 W);Vco (23.06 V), Icc (3.5 A) and for the CdTe:Pm (54.914 W);Vco (35.52 V), Icc (1.546 A). After this characterization test, the modules are exposed to real operating conditions at the Center for Study and Research on the renewable energy (CERER), Cheikh Anta Diop University in Dakar. Four types of shading are performed on each module with the same mask: partial shading at 25%, 50%, 75% and complete shading at 100%. The comparison of the variation rates obtained on the experimental values of the 4 types of shading carried out on each module, shows that, the phenomenon of shading constitutes an environmental factor which influences negatively the maximum power of the thin film PV modules. But this reduction depends on the surface of the shaded module, the nature of the mask but also the technology used. Indeed, for a shading of 25% of the surface of the two modules, we note a reduction of 21.32% of power for the CIGS, against 40.53% for the CdTe/CdS, that is to say a difference which approaches 20%.展开更多
Photo-activities at Inorganic/Organic/Interfaces (IOI) consisting of CdS/ Polyterthiophine (PTTh) assemblies were investigated in nanoparticle suspension and in thin solid film forms. The effects PTTh modifier cause o...Photo-activities at Inorganic/Organic/Interfaces (IOI) consisting of CdS/ Polyterthiophine (PTTh) assemblies were investigated in nanoparticle suspension and in thin solid film forms. The effects PTTh modifier cause on the photoelec-trochemical behavior of the IOI were investigated using [Fe(CN)6]4- as photoactive hydrated electron donor agent. Results show that the adsorption process of [Fe(CN)6]3- (photolysis product) control the photoactivity outcome of IOI assemblies. CdS/PTTh shows lower heterogeneous photochemical response than native CdS. Native CdS amorphous nanoparticles adsorb more [Fe(CN)6]3- with very steady adsorption /desorption process than the modified ones. The interface activities were explained by analyzing the IOI junctions’ characteristics, such as electron affinity, work function and hole/electrons barrier heights. The aqueous nano-systems retained moderate stability as indicated by the reproducibility of their photocatalytic activities. Both [Fe(CN)6]4- and PTTh contributed to the stability of native CdS surfaces.展开更多
Using the first-principles plane-wave calculations within density functional theory, the perfect bi-layer and monolayer terminated WZ-CIS （100）/WZ-CdS （100） interfaces are investigated. After relaxation the atomic...Using the first-principles plane-wave calculations within density functional theory, the perfect bi-layer and monolayer terminated WZ-CIS （100）/WZ-CdS （100） interfaces are investigated. After relaxation the atomic positions and the bond lengths change slightly on the two interfaces. The WZ-CIS/WZ-CdS interfaces can exist stably, when the interface bonding energies are -0.481 J/m2 （bi-layer terminated interface） and -0.677 J/m2 （monolayer terminated interface）. Via analysis of the density of states, difference charge density and Bader charges, no interface state is found near the Fermi level. The stronger adhesion of the monolayer terminated interface is attributed to more electron transformations and orbital hybridizations, promoting stable interfacial bonds between atoms than those on a bi-layer terminated interface.展开更多
In this paper, interface engineering via sputtering of CdO nanolayer at the buffer-CdS/CdTe-absorber interface is demonstrated as an efficient approach to improve the performance of solar cell device. The i-CdO interf...In this paper, interface engineering via sputtering of CdO nanolayer at the buffer-CdS/CdTe-absorber interface is demonstrated as an efficient approach to improve the performance of solar cell device. The i-CdO interfacial layer with various thicknesses from 5 nm to 35 nm was deposited by DC magnetron sputtering. Comparative studies on TCO/CdS/CdTe and TCO/CdS/CdO/CdTe interfaces have been conducted by current-voltage, capacitance-voltage and admittance spectroscopy measurements. The current-voltage characteristics of the devices with an area of 0.45 cm<sup>2</sup> under 100 mW/cm<sup>2</sup> illumination, at the optimum thickness of CdO intermediate layer in the proposed structures, show increases of the short circuit current density and the open circuit voltage by 5% and 25%, respectively. The efficiency improvement of 3.1% of p-i-n cell over p-n cell is observed. Results of the temperature-dependent current-voltage and admittance measurements revealed the removing of the deep level defect with the activation energy of 0.43 eV and the reducing of the ideality factor from 1.9 to 1.8 via buffer/absorber interfacial passivation method. Interface passivation appears to be critical to improve the short circuit current density and the open circuit voltage, and CdO thin film is clearly effective for this purpose.展开更多
In this work, we have modeled and simulated the electrical performance of CIGS thin-film solar cell using one-dimensional simulation software (SCAPS-1D). Starting from a baseline model that reproduced the experimental...In this work, we have modeled and simulated the electrical performance of CIGS thin-film solar cell using one-dimensional simulation software (SCAPS-1D). Starting from a baseline model that reproduced the experimental results, the properties of the absorber layer and the CIGS/Mo interface have been explored, and the requirements for high-efficiency CIGS solar cell were proposed. Simulation results show that the band-gap, acceptor density, defect density are crucial parameters that affect the performance of the solar cell. The best conversion efficiency is obtained when the absorber band-gap is around 1.2 eV, the acceptor density at 10<sup>16</sup> cm<sup><span style="white-space:nowrap;">−</span>3</sup> and the defect density less than 10<sup>14</sup> cm<sup><span style="white-space:nowrap;">−</span>3</sup>. In addition, CIGS/Mo interface has been investigated. It appears that a thin MoSe<sub>2</sub> layer reduces recombination at this interface. An improvement of 1.5 to 2.5 mA/cm<sup>2</sup> in the current density (<em>J<sub>sc</sub></em>) depending on the absorber thickness is obtained.展开更多
Objectives To explore the relationship between CD80 expression on lymphocytes at the fetomaternal interface and the fertility characteristics in CBA/J×DBA/2 mice as a model of recurrent spontaneous abortion (RSA...Objectives To explore the relationship between CD80 expression on lymphocytes at the fetomaternal interface and the fertility characteristics in CBA/J×DBA/2 mice as a model of recurrent spontaneous abortion (RSA) and to investigate the effects of lymphocyte immunotherapy (LIT) on the level of CD80 expression. Materials & Methods The characteristics of fertility in CBA/J×DBA/2 mice were observed in a 120 day period and compared with four normal fertile groups. In another 15 pairs of CBA/J×DBA/2 breedings, resorption rate on day 13 of pregnancy were calculated and the proportion of CD80 + cells at the fetomaternal interface were determined by using two color flow cytometric analysis, mainly stained with CD80 FITC and CD45 PE. In order to determine the identity of CD80 + cells, the expression levels of CD3(T cell marker), DX5(NK cell marker), and MHC II(antigen presenting cell marker) were detected in this cell population. Furthermore, the resorption rate and the proportion of CD80 + cells among CBA/J×DBA/2 breedings with and without immunotherapy were also determined and compared with normal fertile controls. Results The characteristics of abortion in CBA/J×DBA/2 mice were recurrent abortion on about day 10 of gestation. The resorption rate in CBA/J×DBA/2 mice was significantly higher than that in BALB/c×DBA/2 mice (30.8%±16.6% vs. 7.7%±6.7%, P<0.01). Accordingly, the proportion of CD80 + cells evaluated at the fetomaternal interface in CBA/J×DBA/2 mice was also significantly higher (11.7% ±5.8% vs. 3.9%±1.8%, P<0.01). Resorption rate of CBA/J×DBA/2 mice underwent of LIT was significantly lower than that without LIT, and this decreased rate was correlated with decreased proportion of CD80 + cells. Conclusion In CBA/J×DBA/2 mice model, the characteristics of abortion seem to be peri implantation embryo resorption. A correlation between early embryonic waste and higher CD80 proportion at the fetomaternal interface suggests that CD80 + cells may be an important determinant in recurrent peri implantation abortion.展开更多
In the realm of photoenergy conversion,the scarcity of efficient light-driven semiconductors poses a significant obstacle to the advancement of photocatalysis,highlighting the critical need for researchers to explore ...In the realm of photoenergy conversion,the scarcity of efficient light-driven semiconductors poses a significant obstacle to the advancement of photocatalysis,highlighting the critical need for researchers to explore novel semiconductor materials.Herein,we present the inaugural synthesis of a novel semiconductor,CdNCN,under mild conditions,while shedding light on its formation mechanism.By effectively harnessing the[NCN]^(2⁻)moiety in the thiourea process,we successfully achieve the one-pot synthesis of CdNCN-CdS heterostructure photocatalysts.Notably,the optimal CdNCN-CdS sample demonstrates a hydrogen evolution rate of 14.7 mmol g^(-1)h^(-1)under visible light irradiation,establishing itself as the most efficient catalyst among all reported CdS-based composites without any cocatalysts.This outstanding hydrogen evolution performance of CdNCN-CdS primarily arises from two key factors:i)the establishment of an atomic-level N-Cd-S heterostructure at the interface between CdNCN and CdS,which facilitating highly efficient electron transfer;ii)the directed transfer of electrons to the(110)crystal plane of CdNCN,promoting optimal hydrogen adsorption and active participation in the hydrogen evolution reaction.This study provides a new method for synthesizing CdNCN materials and offers insights into the design and preparation of innovative atomic-level composite semiconductor photocatalysts.展开更多
This paper provides the fabrication of Cd-free Cu(In,Ga)Se2(CIGS) solar cells on soda-lime glass substrates. A high quality ZnS buffer layer is grown by chemical bath deposition(CBD) process with ZnSO4-NH3-SC(NH2)2 aq...This paper provides the fabrication of Cd-free Cu(In,Ga)Se2(CIGS) solar cells on soda-lime glass substrates. A high quality ZnS buffer layer is grown by chemical bath deposition(CBD) process with ZnSO4-NH3-SC(NH2)2 aqueous solution system. The X-ray diffraction(XRD) result shows that the as-deposited ZnS film has cubic(111) and(220) diffraction peaks. Scanning electron microscope(SEM) images indicate that the ZnS film has a dense and compact surface with good crystalline quality. Transmission measurement shows that the optical transmittance is about 90% when the wavelength is beyond 500 nm. The bandgap(Eg) value of the as-deposited ZnS film is estimated to be 3.54 eV. Finally, a competitive efficiency of 11.06% is demonstrated for the Cd-free CIGS solar cells with ZnS buffer layer after light soaking.展开更多
基金supported by the National Natural Science Foundation of China(NSFC,Grant No.52372063,62204246 and 52401244)the Young Elite Scientists Sponsorship Program by CAST(Grant No.2023QNRC001)+1 种基金the Postdoctoral Fellowship Program of CPSF(Grant No.GZC20233001,GZC20233006)the China Postdoctoral Science Foundation(Grant No.2024M753526)。
文摘Efficient photocatalytic water splitting can be significantly enhanced through the careful design of S-scheme heterostructures,which play a pivotal role in optimizing performance.Herein,we report the construction of ZnIn_(2)S_(4)/CdS S-scheme heterojunctions under ambient conditions,based on a sonochemical strategy.This structure is facilitated by the well-matched interface between the(007)plane of layered ZnIn_(2)S_(4)and the(101)plane of CdS,leading to a threshold optical response of 2.12 eV,which optimally aligns with visible light absorption.As a proof of concept,the resulting ZnIn_(2)S_(4)/CdS catalysts demonstrate a remarkable improvement in photocatalytic H_(2) evolution,achieving a rate of 5678.2μmol h^(-1)g^(-1)under visible light irradiation(λ>400 nm).This rate is approximately 10 times higher than that of pristine ZnIn_(2)S_(4)nanosheets(NSs)and about 4.6 times higher than that of CdS nanoparticles(NPs),surpassing the performance of most ZnIn_(2)S_(4)-based photocatalysts reported to date.Moreover,they deliver a robust photocatalytic performance during long-term operation of up to 60 h,showing their potential for use in practical applications.Based on the theoretical calculation and experimental results,it is verified that the movements of electrons and holes in the opposite direction could be induced by the disparity in the work function and the internal electric field within the interfaces,thus facilitating the construction of S-scheme heterojunctions,which fundamentally suppresses carrier recombination while minimizing photocorrosion of ZnIn_(2)S_(4)toward enhanced photocatalytic behaviors.
文摘This scientific paper presents a study investigating the effects of defects at the CdS/CIGS and CdS/SDL interfaces on the performance of CIGS solar cells. The objective of this study is to analyze the influence of defects at the interface between the CdS buffer layer and the CIGS absorber, as well as the surface defect layer (SDL), on CIGS solar cell performance. The study explores three key aspects: the impact of the conduction band offset (CBO) at the CdS/CIGS interface, the effects of interface defects and defect density on performance, and the combined influence of CBO and defect density at the CdS/ SDL and SDL/CIGS interfaces. For interface defects not exceeding 10<sup>13</sup> cm<sup>-2</sup>, we obtained a good efficiency of 22.9% when -0.1 eV analyzing the quality of CdS/SDL and SDL/CIGS junctions, it appears that defects at the SDL/CIGS interface have very little impact on the performances of the CIGS solar cell. By optimizing the electrical parameters of the CdS/SDL interface defects, we achieved a conversion efficiency of 23.1% when -0.05 eV < CBO < 0.05 eV.
基金supported by the National Natural Science Foundation of China(Grant Nos.11364025 and 11164014)the Gansu Science and Technology PillarProgram,China(Grant No.1204GKCA057)
文摘Using first-principles calculations within density functional theory, we study the atomic structures and electronic properties of the perfect and defective （2VCu＋ Incu） CulnGaSe2/CdS interfaces theoretically, especially the interface states. We find that the local lattice structure of （2VCu＋ InCu） interface is somewhat disorganized. By analyzing the local density of states projected on several atomic layers of the two interfaces models, we find that for the （2VCu＋InCu） interface the interface states near the Fermi level in CulnGaSe2 and CdS band gap regions are mainly composed of interracial Se-4p, Cu-3d and S-3p orbitals, while for the perfect interface there are no clear interface states in the CulnGaSe2 region but only some interface states which are mainly composed of S-3p orbitals in the valance band of CdS region.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.62074037,61574038,51961165108,and 51972332)the Natural Science Foundation of Fujian Province,China(Grant No.2017J01503)+2 种基金the Education and Scientific Research Project of Fujian Province,China(Grant No.JAT190010)the Open Project Program of the State Key Laboratory of Photocatalysis on Energy and Environment,China(Grant No.SKLPEE-202011)Fuzhou University,China。
文摘Flexible Cu2ZnSn(S,Se)4(CZTSSe)solar cells show great potential applications due to low-cost,nontoxicity,and stability.The device performances under an especial open circuit voltage(VOC)are limited by the defect recombination of CZTSSe/CdS heterojunction interface.We improve the deposition technique to obtain compact CdS layers without any pinholes for flexible CZTSSe solar cells on Mo foils.The efficiency of the device is improved from 5.7%to 6.86%by highquality junction interface.Furthermore,aiming at the S loss of CdS film,the S source concentration in deposition process is investigated to passivate the defects and improve the CdS film quality.The flexible Mo-foil-based CZTSSe solar cells are obtained to possess a 9.05%efficiency with a VOC of 0.44 V at an optimized S source concentration of 0.68 mol/L.Systematic physical measurements indicate that the S source control can effectively suppress the interface recombination and reduce the VOCdeficit.For the CZTSSe device bending characteristics,the device efficiency is almost constant after1000 bends,manifesting that the CZTSSe device has an excellent mechanical flexibility.The effective improvement strategy of CdS deposition is expected to provide a new perspective for promoting the conversion efficiency of CZTSSe solar cells.
基金supported by the National Natural Science Foundation of China(22162008,22162007)the Science and Technology Supporting Project of Guizhou Province([2022]208,[2021]480)the Basic Research Program of Science&Technology Department of Guizhou Province([2020]1Y055)。
文摘Interface engineering can improve the charge separation efficiency and inhibit photocorrosion is an emerging direction of developing more efficient and cost-effective photocatalytic systems.Herein,we report the sulfur-confined intimate Cd S intergrown Cd(Cd S/Cd)Ohmic junction(peanut-chocolate-ball like)for high-efficient H2production with superior anti-photocorrosion ability,which was fabricated from in-situ photoreduction of CdS intergrown Cd2SO4(OH)2(CdS/Cd2SO4(OH)2)prepared through a facile space-controlled-solvothermal method.The ratios of CdS/Cd can be effectively controlled by tunning that of CdS/Cd2SO4(OH)2which were prepared by adjusting the volume of reaction liquid and the remaining space of the reactor.Experiments investigations and density functional theory(DFT)calculations reveal that the Cd S intergrown Cd Ohmic junction interfaces(with appropriate content Cd intergrown on Cd S(19.54 wt%))are beneficial in facilitating the transfer of photogenerated electrons by constructing an interfacial electric field and forming sulfur-confined structures for preventing the positive holes(h+)oxidize the Cd S.This contributes to a high photocatalytic H2production activity of 95.40μmol h-1(about 32.3 times higher than bare Cd S)and possesses outstanding photocatalytic stability over 205 h,much longer than most Cd S-based photocatalysts previously reported.The interface engineering design inspired by the structure of peanut-chocolate-ball can greatly promote the future development of catalytic systems for wider application.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61176044 and 11074224)the Science and Technology Project for Innovative Scientist of Henan Province,China(Grant No.1142002510017)the Science and Technology Project on Key Problems of Henan Province,China(Grant No.082101510007)
文摘The electron transport behavior across the interface plays an important role in determining the performance of op- toelectronic devices based on heterojunctions. Here through growing CdS thin film on silicon nanoporous pillar array, an untraditional, nonplanar, and multi-interface CdS/Si nanoheterojunction is prepared. The current density versus voltage curve is measured and an obvious rectification effect is observed. Based on the fitting results and model analyses on the forward and reverse conduction characteristics, the electron transport mechanism under low forward bias, high forward bias, and reverse bias are attributed to the Ohmic regime, space-charge-limited current regime, and modified Poole-Frenkel regime respectively. The forward and reverse electrical behaviors are found to be highly related to the distribution of inter- facial trap states and the existence of localized electric field respectively. These results might be helpful for optimizing the preparing procedures to realize high-performance silicon-based CdS optoelectronic devices.
基金supported by the National Natural Science Foundation of China (Nos. 50990063, 51261130582 and 91233114)
文摘Improved hybrid solar cells consisting of vertical aligned cadmium sulfide （CdS） nanorod arrays and interpenetrating polythiophene （P3HT） have been achieved via modification of CdS nanorod surface by using conjugated N719 dye. The complete infiltration of P3HT between CdS nanorods interspacing was verified by scanning electron microscopy. By employing absorption and photoluminescence spectra, and current-voltage characterization the interaction between N719 molecules and CdS nanorods/P3HT interface was explored, and the role of N719 dye on the improvement of device performance was discussed.
基金Project supported by the Natural Science Foundation of Shanghai (Grant No.13ZR1428200)
文摘Highly crystalline and transparent CdS films are grown by utilizing the vacuum thermal evaporation （VTE） method. The structural, surface morphological, and optical properties of the films are studied and compared with those prepared by chemical bath deposition （CBD）. It is found that the films deposited at a high substrate temperature （200 ℃） have a preferential orientation along （002） which is consistent with CBD-grown films. Absorption spectra reveal that the films are highly transparent and the optical band gap values are found to be in a range of 2.44 eV-2.56 eV. Culnl_xGaxSe2 （CIGS） solar cells with in-situ VTE-grown CdS films exhibit higher values of Voc together with smaller values of Jsc than those from CBD. Eventually the conversion efficiency and fill factor become slightly better than those from the CBD method. Our work suggests that the in-situ thermal evaporation method can be a competitive alternative to the CBD method, particularly in the physical- and vacuum-based CIGS technology.
文摘In this paper, a comparative study of the maximum power on the shading rate on the maximum power of thin film PV modules. Thus two thin film PV modules of type Copper indium gallium selenide, CIGS, of 90W power and a CdTe (Cadmium telluride)/CdS (Cadmium sulfide) module, of maximum power 75 W. These modules, reference SN-CIGS90 and CX3 75 were tested under the conditions of the installation site to ensure their proper functioning and to determine the initial values of electrical parameters before shading. The results obtained are as follows: for the CIGS: Pm (80.717 W);Vco (23.06 V), Icc (3.5 A) and for the CdTe:Pm (54.914 W);Vco (35.52 V), Icc (1.546 A). After this characterization test, the modules are exposed to real operating conditions at the Center for Study and Research on the renewable energy (CERER), Cheikh Anta Diop University in Dakar. Four types of shading are performed on each module with the same mask: partial shading at 25%, 50%, 75% and complete shading at 100%. The comparison of the variation rates obtained on the experimental values of the 4 types of shading carried out on each module, shows that, the phenomenon of shading constitutes an environmental factor which influences negatively the maximum power of the thin film PV modules. But this reduction depends on the surface of the shaded module, the nature of the mask but also the technology used. Indeed, for a shading of 25% of the surface of the two modules, we note a reduction of 21.32% of power for the CIGS, against 40.53% for the CdTe/CdS, that is to say a difference which approaches 20%.
文摘Photo-activities at Inorganic/Organic/Interfaces (IOI) consisting of CdS/ Polyterthiophine (PTTh) assemblies were investigated in nanoparticle suspension and in thin solid film forms. The effects PTTh modifier cause on the photoelec-trochemical behavior of the IOI were investigated using [Fe(CN)6]4- as photoactive hydrated electron donor agent. Results show that the adsorption process of [Fe(CN)6]3- (photolysis product) control the photoactivity outcome of IOI assemblies. CdS/PTTh shows lower heterogeneous photochemical response than native CdS. Native CdS amorphous nanoparticles adsorb more [Fe(CN)6]3- with very steady adsorption /desorption process than the modified ones. The interface activities were explained by analyzing the IOI junctions’ characteristics, such as electron affinity, work function and hole/electrons barrier heights. The aqueous nano-systems retained moderate stability as indicated by the reproducibility of their photocatalytic activities. Both [Fe(CN)6]4- and PTTh contributed to the stability of native CdS surfaces.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11164014 and 11364025)the Gansu Science and Technology Pillar Program,China(Grant No.1204GKCA057)
文摘Using the first-principles plane-wave calculations within density functional theory, the perfect bi-layer and monolayer terminated WZ-CIS （100）/WZ-CdS （100） interfaces are investigated. After relaxation the atomic positions and the bond lengths change slightly on the two interfaces. The WZ-CIS/WZ-CdS interfaces can exist stably, when the interface bonding energies are -0.481 J/m2 （bi-layer terminated interface） and -0.677 J/m2 （monolayer terminated interface）. Via analysis of the density of states, difference charge density and Bader charges, no interface state is found near the Fermi level. The stronger adhesion of the monolayer terminated interface is attributed to more electron transformations and orbital hybridizations, promoting stable interfacial bonds between atoms than those on a bi-layer terminated interface.
文摘In this paper, interface engineering via sputtering of CdO nanolayer at the buffer-CdS/CdTe-absorber interface is demonstrated as an efficient approach to improve the performance of solar cell device. The i-CdO interfacial layer with various thicknesses from 5 nm to 35 nm was deposited by DC magnetron sputtering. Comparative studies on TCO/CdS/CdTe and TCO/CdS/CdO/CdTe interfaces have been conducted by current-voltage, capacitance-voltage and admittance spectroscopy measurements. The current-voltage characteristics of the devices with an area of 0.45 cm<sup>2</sup> under 100 mW/cm<sup>2</sup> illumination, at the optimum thickness of CdO intermediate layer in the proposed structures, show increases of the short circuit current density and the open circuit voltage by 5% and 25%, respectively. The efficiency improvement of 3.1% of p-i-n cell over p-n cell is observed. Results of the temperature-dependent current-voltage and admittance measurements revealed the removing of the deep level defect with the activation energy of 0.43 eV and the reducing of the ideality factor from 1.9 to 1.8 via buffer/absorber interfacial passivation method. Interface passivation appears to be critical to improve the short circuit current density and the open circuit voltage, and CdO thin film is clearly effective for this purpose.
文摘In this work, we have modeled and simulated the electrical performance of CIGS thin-film solar cell using one-dimensional simulation software (SCAPS-1D). Starting from a baseline model that reproduced the experimental results, the properties of the absorber layer and the CIGS/Mo interface have been explored, and the requirements for high-efficiency CIGS solar cell were proposed. Simulation results show that the band-gap, acceptor density, defect density are crucial parameters that affect the performance of the solar cell. The best conversion efficiency is obtained when the absorber band-gap is around 1.2 eV, the acceptor density at 10<sup>16</sup> cm<sup><span style="white-space:nowrap;">−</span>3</sup> and the defect density less than 10<sup>14</sup> cm<sup><span style="white-space:nowrap;">−</span>3</sup>. In addition, CIGS/Mo interface has been investigated. It appears that a thin MoSe<sub>2</sub> layer reduces recombination at this interface. An improvement of 1.5 to 2.5 mA/cm<sup>2</sup> in the current density (<em>J<sub>sc</sub></em>) depending on the absorber thickness is obtained.
基金National Key Fundamental Research Plan(" 973") Project( G1 9990 50 43 0 3 ) ,China
文摘Objectives To explore the relationship between CD80 expression on lymphocytes at the fetomaternal interface and the fertility characteristics in CBA/J×DBA/2 mice as a model of recurrent spontaneous abortion (RSA) and to investigate the effects of lymphocyte immunotherapy (LIT) on the level of CD80 expression. Materials & Methods The characteristics of fertility in CBA/J×DBA/2 mice were observed in a 120 day period and compared with four normal fertile groups. In another 15 pairs of CBA/J×DBA/2 breedings, resorption rate on day 13 of pregnancy were calculated and the proportion of CD80 + cells at the fetomaternal interface were determined by using two color flow cytometric analysis, mainly stained with CD80 FITC and CD45 PE. In order to determine the identity of CD80 + cells, the expression levels of CD3(T cell marker), DX5(NK cell marker), and MHC II(antigen presenting cell marker) were detected in this cell population. Furthermore, the resorption rate and the proportion of CD80 + cells among CBA/J×DBA/2 breedings with and without immunotherapy were also determined and compared with normal fertile controls. Results The characteristics of abortion in CBA/J×DBA/2 mice were recurrent abortion on about day 10 of gestation. The resorption rate in CBA/J×DBA/2 mice was significantly higher than that in BALB/c×DBA/2 mice (30.8%±16.6% vs. 7.7%±6.7%, P<0.01). Accordingly, the proportion of CD80 + cells evaluated at the fetomaternal interface in CBA/J×DBA/2 mice was also significantly higher (11.7% ±5.8% vs. 3.9%±1.8%, P<0.01). Resorption rate of CBA/J×DBA/2 mice underwent of LIT was significantly lower than that without LIT, and this decreased rate was correlated with decreased proportion of CD80 + cells. Conclusion In CBA/J×DBA/2 mice model, the characteristics of abortion seem to be peri implantation embryo resorption. A correlation between early embryonic waste and higher CD80 proportion at the fetomaternal interface suggests that CD80 + cells may be an important determinant in recurrent peri implantation abortion.
基金financially supported by the National Natural Science Foundation of China(Nos.22078118,22274059 and 42277219)the Natural Science Foundation of Guangdong Province,China(Nos.2023A1515010740 and 2023A1515030131).
文摘In the realm of photoenergy conversion,the scarcity of efficient light-driven semiconductors poses a significant obstacle to the advancement of photocatalysis,highlighting the critical need for researchers to explore novel semiconductor materials.Herein,we present the inaugural synthesis of a novel semiconductor,CdNCN,under mild conditions,while shedding light on its formation mechanism.By effectively harnessing the[NCN]^(2⁻)moiety in the thiourea process,we successfully achieve the one-pot synthesis of CdNCN-CdS heterostructure photocatalysts.Notably,the optimal CdNCN-CdS sample demonstrates a hydrogen evolution rate of 14.7 mmol g^(-1)h^(-1)under visible light irradiation,establishing itself as the most efficient catalyst among all reported CdS-based composites without any cocatalysts.This outstanding hydrogen evolution performance of CdNCN-CdS primarily arises from two key factors:i)the establishment of an atomic-level N-Cd-S heterostructure at the interface between CdNCN and CdS,which facilitating highly efficient electron transfer;ii)the directed transfer of electrons to the(110)crystal plane of CdNCN,promoting optimal hydrogen adsorption and active participation in the hydrogen evolution reaction.This study provides a new method for synthesizing CdNCN materials and offers insights into the design and preparation of innovative atomic-level composite semiconductor photocatalysts.
基金supported by the Fundamental Research Funds for the Central Universities(No.65011991)the Specialized Research Fund for the Doctoral Program of Higher Education(No.BE033511)
文摘This paper provides the fabrication of Cd-free Cu(In,Ga)Se2(CIGS) solar cells on soda-lime glass substrates. A high quality ZnS buffer layer is grown by chemical bath deposition(CBD) process with ZnSO4-NH3-SC(NH2)2 aqueous solution system. The X-ray diffraction(XRD) result shows that the as-deposited ZnS film has cubic(111) and(220) diffraction peaks. Scanning electron microscope(SEM) images indicate that the ZnS film has a dense and compact surface with good crystalline quality. Transmission measurement shows that the optical transmittance is about 90% when the wavelength is beyond 500 nm. The bandgap(Eg) value of the as-deposited ZnS film is estimated to be 3.54 eV. Finally, a competitive efficiency of 11.06% is demonstrated for the Cd-free CIGS solar cells with ZnS buffer layer after light soaking.
