Cosensitization based on two or multiple dyes as "dye cocktails" can hit the target on compensating and broadening light-harvesting region.Two indoline D-A-π-A motif sensitizers(WS-2 and WS-39) that possess...Cosensitization based on two or multiple dyes as "dye cocktails" can hit the target on compensating and broadening light-harvesting region.Two indoline D-A-π-A motif sensitizers(WS-2 and WS-39) that possess similar light response area but distinctly reversed feature in photovoltaic performance are selected as the specific cosensitization couple. That is, WS-2 shows quite high photocurrent but low photovoltage, and WS-39 gives relatively low photocurrent but quite high photo voltage. Due to the obvious "barrel effect",both dyes show medium PCE around8.50%. In contrast with the previous cosensitization strategy mostly focused on the compensation of light response region, herein we perform different cosensitization sequence, for taking insight into the balance of photocurrent and photo voltage, and achieving the synergistic improvement in power conversion efficiency(PCE). Electronic impedance spectra(EIS) indicate that exploiting dye WS-39 with high V_(OC) value as the primary sensitizer can repress the charge recombination more effectively, resulting in superior V_(OC) rather than using dye WS-2 with high J_(SC)as the primary sensitizer. As a consequence, a high PCE value of 9.48% is obtained with the delicate cosensitization using WS-39 as primary dye and WS-2 as accessory dye, which is higher than the corresponding devices sensitized by each individual dye(around 8.48-8.67%). It provides an effective optimizing strategy of cosensitization how to combine the individual dye advantages for developing highly efficient solar cells.展开更多
Small-molecule organic solar cells(SMOSCs)have attracted considerable attention owing to the merits of small molecules,such as easy purification,well-defined chemical structure.To achieve high-performance SMOSCs,the r...Small-molecule organic solar cells(SMOSCs)have attracted considerable attention owing to the merits of small molecules,such as easy purification,well-defined chemical structure.To achieve high-performance SMOSCs,the rational design of well-matched donor and acceptor materials is extremely essential.In this work,two new small molecular donor materials with subtle change in the conjugated side thiophene rings are synthesized.The subtle change significantly affects the photovoltaic performance of molecular donors.Compared with chlorinated molecule MDJ-Cl,the non-chlorinated analogue MDJ exhibits decreased miscibility with the non-fullerene acceptor Y6,can more efficiently quench the excitons of Y6.As a result,a improved PCE of 11.16% is obtained for MDJ:Y6 based SMOSCs.The results highlight the importance of fine-tuning the molecular structure to achieve high-performance SMOSCs.展开更多
Organic photovoltaics(OPVs)have achieved remarkable progress,with laboratory-scale single-junction devices now demonstrating power conversion efficiencies(PCEs)exceeding 20%.However,these efficiencies are highly depen...Organic photovoltaics(OPVs)have achieved remarkable progress,with laboratory-scale single-junction devices now demonstrating power conversion efficiencies(PCEs)exceeding 20%.However,these efficiencies are highly dependent on the thickness of the photoactive layer,which is typically around 100 nm.This sensitivity poses a challenge for industrial-scale fabrication.Achieving high PCEs in thick-film OPVs is therefore essential.This review systematically examines recent advancements in thick-film OPVs,focusing on the fundamental mechanisms that lead to efficiency loss and strategies to enhance performance.We provide a comprehensive analysis spanning the complete photovoltaic process chain:from initial exciton generation and diffusion dynamics,through dissociation mechanisms,to subsequent charge-carrier transport,balance optimization,and final collection efficiency.Particular emphasis is placed on cutting-edge solutions in molecular engineering and device architecture optimization.By synthesizing these interdisciplinary approaches and investigating the potential contributions in stability,cost,and machine learning aspects,this work establishes comprehensive guidelines for designing high-performance OPVs devices with minimal thickness dependence,ultimately aiming to bridge the gap between laboratory achievements and industrial manufacturing requirements.展开更多
N-cetylpyridinium iodide(N-CPI)as a new electric additive for enhancing photovoltaic performance of the dye-sensitized solar cell(DSSC)was studied.It showed high efficiency for enhancing both the open-circuit voltage ...N-cetylpyridinium iodide(N-CPI)as a new electric additive for enhancing photovoltaic performance of the dye-sensitized solar cell(DSSC)was studied.It showed high efficiency for enhancing both the open-circuit voltage and the short-circuit current density of DSSC when the suitable amount of N-CPI as 0.02 M was added in liquid electrolyte.The energy conversion effi-ciency of DSSC increased from 4.429%to 6.535%,with 47.55%enhancement.Therefore,it is a highly efficient electric addi-tive for DSSC.The intrinsic reason is owing to the special molecular structure of N-CPI,which contains two different polarity groups.As a surfactant,N-CPI could form ordered arrangement in liquid electrolyte,which affects the diffusing ability and the redox reaction of I-/I3-,and further affects the photovoltaic performance of DSSC.展开更多
Three model polythiophenes,PTCBT,PTCFBT and PFTCBT,have been synthesized to investigate the effect of fluorination on photovoltaic performance of polythiothenes.Compared with PTCBT,PFTCBT with F atom on TC unit shows ...Three model polythiophenes,PTCBT,PTCFBT and PFTCBT,have been synthesized to investigate the effect of fluorination on photovoltaic performance of polythiothenes.Compared with PTCBT,PFTCBT with F atom on TC unit shows a narrower optical bandgap(1.79 eV),higher crystallinity,and ideal morphology in the active layer,leading to a higher short-circuit current density(J_(SC))of 11.84 mA/cm^2 and a power conversion efficiency(PCE)of 5.93%.The lock-up function of fluorine enhances polythiophene backbone planarity and molecular packing.展开更多
The microstructure of the active layer in organic photovoltaics(OPVs),such as the size of phase separation,purity of the phases,and molecular packing within each phase,plays a crucial role in influencing the behavior ...The microstructure of the active layer in organic photovoltaics(OPVs),such as the size of phase separation,purity of the phases,and molecular packing within each phase,plays a crucial role in influencing the behavior of excitons and charge carriers within the active layer.It is also a key determinant of the photovoltaic performance of the device.During the optimization of OPV devices,the use of additives has been demonstrated to be an effective strategy in microstructure control,leading to enhanced performance.Therefore,the quest for stable and efficient novel additives,along with an exploration and summarization of the mechanisms underlying additive-induced microstructure control,is essential for a better understanding of the developmental trends of high-performance additives.In this review,we categorize additives based on their chemical structures and discuss their effects on the microstructure of the active layer from both thermodynamic and kinetic perspectives.Furthermore,we elaborate on the working mechanisms and their impact on the photovoltaic performance of the devices.This review provides an overview of recent advances in additives for OPVs,offering potential guidance for the future development of additives and further optimization of the active layer in photovoltaic devices.展开更多
Hole-transporting materials play a vital role in terms of the performance of perovskite solar cells(PSCs).The dithieno[3,2-b:2’,3’-d]pyrrole(DTP),an S,N-heterocyclic building block,has been proved to be desirable fo...Hole-transporting materials play a vital role in terms of the performance of perovskite solar cells(PSCs).The dithieno[3,2-b:2’,3’-d]pyrrole(DTP),an S,N-heterocyclic building block,has been proved to be desirable for molecular design of hole-transporting materials in PSCs.We developed an asymmetrically substituted DTP small-molecule(JW12)and a reference compound(JW11).The asymmetrical structure of JW12 leads to different absorption properties and electron distribution.The device in a planar n-i-p architecture using JW12 shows a much higher PCE(18.07%)than that based on JW11(15.46%),which is also better than the device based on spiro-OMe TAD(17.47%).We hope our research can provide a new perspective in molecular design of organic HTMs for perovskite solar cells.展开更多
In this work,the photovoltaic properties of BFBPD-PC61 BM system as a promising high-performance organic solar cell（OSC） were theoretically investigated by means of quantum chemistry and molecular dynamics calculati...In this work,the photovoltaic properties of BFBPD-PC61 BM system as a promising high-performance organic solar cell（OSC） were theoretically investigated by means of quantum chemistry and molecular dynamics calculations coupled with the incoherent charge-hopping model.Moreover,the hole carrier mobility of BFBPD thin-film was also estimated with the aid of an amorphous cell including 100 BFBPD molecules.Results revealed that the BFBPD-PC61 BM system possesses a middle-sized open-circuit voltage of 0.70 V,large short-circuit current density of 17.26 mA ·cm^-2,high fill factor of 0.846,and power conversion efficiency of 10%.With the Marcus model,in the BFBPD-PC61 BM interface,the exciton-dissociation rate,kdis,was predicted to be 2.684×10^13 s^-1,which is as 3-5 orders of magnitude large as the decay（radiative and non-radiative） one（10-8-10^10s^-1）,indicating a high exciton-dissociation efficiency of 100% in the BFBPD-PC61 BM interface.Furthermore,by the molecular dynamics simulation,the hole mobility of BFBPD thin-film was predicted to be as high as 1.265 × 10^-2 cm-2·V^-1·s^-1,which can be attributed to its dense packing in solid state.展开更多
Lead-based organic-inorganic hybrid perovskites have exhibited great potential in photovoltaics,achieving power conversion efficiencies(PCEs) exceeding 25%.However,the toxicity of lead and the instability of these mat...Lead-based organic-inorganic hybrid perovskites have exhibited great potential in photovoltaics,achieving power conversion efficiencies(PCEs) exceeding 25%.However,the toxicity of lead and the instability of these materials under moist conditions pose significant barriers to large-scale production.To overcome these limitations,researchers have proposed mixed-valence double perovskites,where Cs_(2)Au~ⅠAu~ⅢI_6 is a particularly effective absorber due to its suitable band gap and high absorptance efficiency.To further extend the scope of these lead-free materials,we varied the trivalent gold ion and halogen anion in Cs_(2)Au~ⅠAu~ⅢI_6,resulting in 18 new structures with unique properties.Further,using first-principles calculations and elimination criteria,we identified four materials with ideal band gaps,small effective carrier mass,and strong anisotropic optical properties.According to theoretical modeling,Cs_(2)AuSbCl_6,Cs_(2)AuInCl_6,and Cs_(2)AuBiCl_6 are potential candidates for solar cell absorbers,with a spectroscopic limited maximum efficiency(SLME) of approximately 30% in a 0.25 μm-thick film.These three compounds have not been previously reported,and therefore,our work provides new insights into potential materials for solar energy conversion.We aim for this theoretical exploration of novel perovskites to guide future experiments and accelerate the development of high-performance photovoltaic devices.展开更多
The porphyrin derivatives, 5,10,15,20-tetra（4-（N-pentane-carboxamide） phenyl） porphyrin（4 NC5-TPP）, 5,10,15,20-tetra（4-（N-dodecane-carboxamide） phenyl） porphyrin（4 NC12-TPP） and their zinc-complexes（4 NC5...The porphyrin derivatives, 5,10,15,20-tetra（4-（N-pentane-carboxamide） phenyl） porphyrin（4 NC5-TPP）, 5,10,15,20-tetra（4-（N-dodecane-carboxamide） phenyl） porphyrin（4 NC12-TPP） and their zinc-complexes（4 NC5-TPPZn and 4 NC12-TPPZn）, have been synthesized. Their thermal properties and morphologies were investigated via thermal gravity analysis（TGA）, differential scanning calorimetry（DSC） and polarized optical microscopy（POM）. It was found that the 4 NC5-TPP was amorphous and the 4 NC5-TPPZn was crystalline at room temperature, while the 4 NC12-TPP formed the columnar liquid crystal and the 4 NC12-TPPZn showed the spherulite texture. The electron state density distributions and the optimum configuration of the porphyrin derivatives were calculated by chemical simulation. The electrochemical oxidation and reduction abilities of the porphyrin derivatives were studied by cyclic voltammetry（CV）. It was indicated that the porphyrin derivatives had the potential to develop organic photovoltaic（OPV） devices. Using the porphyrin derivatives as donor materials and the 3,4,9,10-perylenetetracarboxylic dianhydride（PTCDA） as the acceptor material, the OPV devices were fabricated. The device structure is ITO/porphyrin derivatives：PTCDA/Al. The relationship between the morphology and performance of OPV was studied. It was found that the crystalline morphology of the film was beneficial to improve the efficiency of the devices.展开更多
Ho^3＋-doped titanium dioxide（TiO2：Ho^3＋） downconversion（DC） nanowires were synthesized through a simple hydrothermal method followed by a subsequent calcination process after being immersed in Ho（NO3）3 aqueou...Ho^3＋-doped titanium dioxide（TiO2：Ho^3＋） downconversion（DC） nanowires were synthesized through a simple hydrothermal method followed by a subsequent calcination process after being immersed in Ho（NO3）3 aqueous solution. Moreover, TiO2：Ho^3＋ nanowires（HTNWs） were used as the photoanode in dye-sensitized solar cells（DSSCs） to investigate their photoelectric properties. Scanning electron microscopy（SEM） and X-ray diffraction（XRD） were used to characterize the morphology and structure of the material, respectively. The photofluorescence and ultraviolet-visible absorption spectra of HTNWs reveal a DC from the near and middle ultraviolet light to visible light which matches the strong absorbed region of the N719 dye. Compared with the pure TNW photoanode, HTNWs DC photoanodes show greater photovoltaic efficiency. The photovoltaic conversion efficiency（η） of the DSSCs with HTNWs photoanode doped with 4% Ho2O3（mass fraction） is two times that with pure TNW photoanode. This enhancement could be attributed to HTNWs which could extend the spectral response range of DSSCs to the near and middle ultraviolet region and increase the short-circuit current density（Jsc） of DSSCs, thus leading to the enhancement of photovoltaic conversion efficiency.展开更多
The commercialized poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)is usually used as hole transport layers(HTLs)in tin-based perovskite solar cells(TPSCs).However,the further development has been re...The commercialized poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)is usually used as hole transport layers(HTLs)in tin-based perovskite solar cells(TPSCs).However,the further development has been restricted due to the acidity that could damage the stability of TPSCs.Although the PEDOT:PSS solution can be diluted by water to decrease acidity and reduce the cost of device fabrication,the electrical conductivity will decrease obviously in diluted PEDOT:PSS solution.Herein,potassium thiocyanate(KSCN)is selected to regulate the properties of PEDOT:PSS HTLs from the diluted PEDOT:PSS aqueous solution by water with a volume ratio of 1:1 to prepare efficient TPSCs.The effect of KSCN addition on the structure and photoelectrical properties of PEDOT:PSS HTLs and TPSCs have been systematically studied.At the optimal KSCN concentration,the TPSCs based on KSCN-doped PEDOT:PSS HTLs(KSCN-PSCs)demonstrate the champion power conversion efficiency(PCE)of 8.39%,while the reference TPSCs only show a champioan PCE of 6.70%.The further analysis demonstrates that the KSCN additive increases the electrical conductivity of HTLs prepared by the diluted PEDOT:PSS solution,improves the microstructure of perovskite film,and inhibits carrier recombination in TPSCs,leading to the reduced hysteresis effect and enhanced PCE in KSCN-PSCs.This work gives a low-cost and practical strategy to develop a high-quality PEDOT:PSS HTLs from diluted PEDOT:PSS aqueous solution for efficient TPSCs.展开更多
6,7-Dialkoxy-2,3-diphenylquinoxaline based narrow band gap conjugated polymers, poly[2,7-（9-octyl-9H- carbazole）-alt-5,5-（5,8-di-2-thinenyl-（6,7-dialkoxy-2,3-diphenylquinoxaline））] （PCDTQ） and poly[2,7-（9,9-d...6,7-Dialkoxy-2,3-diphenylquinoxaline based narrow band gap conjugated polymers, poly[2,7-（9-octyl-9H- carbazole）-alt-5,5-（5,8-di-2-thinenyl-（6,7-dialkoxy-2,3-diphenylquinoxaline））] （PCDTQ） and poly[2,7-（9,9-dioctylfluorene）- alt-5,5-（5,8-di-2-thinenyl-（6,7-dialkoxy-2,3-diphenylquinoxaline））] （PFDTQ）, have been synthesized by Suzuki polycondensation. Their optical, electrochemical, transport and photovoltaic properties have been investigated in detail. Hole mobilities of PCDTQ and PFDTQ films spin coated from 1,2-dichlorobenzene （DCB） solutions are 1.0 X 10-4 and 4.1 X 10-4 cm2 V-1 s-l, respectively. Polymer solar cells were fabricated with the as-synthesized polymers as the donor and PC61BM and PC7 IBM as the acceptor. Devices based on PCDTQ：PC71BM （1：3） and PFDTQ：PC7 IBM （1：3） fabricated from DCB solutions demonstrated a power conversion efficiency （PCE） of 2.5% with a Voc of 0.95 V and a PCE of 2.5% with a Voof 0.98 V, respectively, indicating they are promising donor materials.展开更多
The pure TiO2 and Fe salts [Fe（C2O4）3,5H2O]-doped TiO2 electrodes were prepared by the hydrothermal method. The pure TiO2 or Fe-doped TiO2 slurry was coated onto the fluorine-doped tin oxide glass substrate by the D...The pure TiO2 and Fe salts [Fe（C2O4）3,5H2O]-doped TiO2 electrodes were prepared by the hydrothermal method. The pure TiO2 or Fe-doped TiO2 slurry was coated onto the fluorine-doped tin oxide glass substrate by the Doctor Blade method and then sintered at 450 ℃. The Mott-Schottks, plot indicates that the fiat band potential of TiO2 was shifted positively after Fe-doped TiO2. The positive shift of the fiat band potential improves the driving force of injected electrons from the LUMO of the dye to the conduction band of TiO2. This study shows that photovoltaic efficiency increased by 22.9% from 6.07% to 7.46% compared to pure TiO2, and the fill factors increased from 0.53 to 0.63.展开更多
According to the good charge transporting property of perovskite, we design and simulate a p–i–n-type all-perovskite solar cell by using one-dimensional device simulator. The perovskite charge transporting layers an...According to the good charge transporting property of perovskite, we design and simulate a p–i–n-type all-perovskite solar cell by using one-dimensional device simulator. The perovskite charge transporting layers and the perovskite absorber constitute the all-perovskite cell. By modulating the cell parameters, such as layer thickness values, doping concentrations and energy bands of n-, i-, and p-type perovskite layers, the all-perovskite solar cell obtains a high power conversion efficiency of 25.84%. The band matched cell shows appreciably improved performance with widen absorption spectrum and lowered recombination rate, so weobtain a high J_（sc） of 32.47 m A/cm^2. The small series resistance of the all-perovskite solar cell also benefits the high J_（sc）. The simulation provides a novel thought of designing perovskite solar cells with simple producing process, low production cost and high efficient structure to solve the energy problem.展开更多
Three novel triarylamine dyes（AFL1-AFL3） containing fluorenyl and the biphenyl moieties have been designed and synthesized for application in dye-sensitized solar cells.The light-harvesting capabilities and photovol...Three novel triarylamine dyes（AFL1-AFL3） containing fluorenyl and the biphenyl moieties have been designed and synthesized for application in dye-sensitized solar cells.The light-harvesting capabilities and photovoltaic performance of these dyes were investigated systematically through comparison of different π-bridges.The dye with a furan linker exhibited a higher open-circuit voltage（VOC） and monochromatic incident photon-to-current conversion efficiency（IPCE） compared to thiophene and benzene linker.Thus,AFL3 containing a furan linker exhibited the maximum overall conversion efficiency of 5.81%（VOC = 760 mV,JSC = 11.36 mA cm^-2 and ff=0.68） under standard global AM 1.5 G solar condition.展开更多
CdSe/CdS semiconductor quantum dots co-sensitized TiO2 nanorod array was fabricated on the transparent conductive fluorine-doped tin oxide （FTO） substrate using the hydrothermal and successive ionic layer adsorption...CdSe/CdS semiconductor quantum dots co-sensitized TiO2 nanorod array was fabricated on the transparent conductive fluorine-doped tin oxide （FTO） substrate using the hydrothermal and successive ionic layer adsorption and reaction （SILAR） process. The structural and morphological properties of the samples were characterized by X-ray diffraction （XRD）, field-emission scanning electron microscopy （FESEM）, and transmission electron microscopy （TEM）. The results indicate that CdSe/CdS QDs are uniformly coated on the surface of the TiO2 nanorods. The shift of light absorption edge was monitored by taking UV-visible absorption spectra. Compared with the absorption spectra of the TiO2 nanorod array, deposition of CdSe/CdS QDs shifts the absorption edge to the higher wavelength. The enhanced light absorption in the visible-light region of CdSe/CdS/TiO2 nanorod array indicates that CdSe/CdS layers can act as co-sensitizers in quantum dots sensitized solar cells （QDSSCs）. By optimizing the CdSe layer deposition cycles, a photocurrent of 5.78 mA/cm2, an open circuit photovoltage of 0.469 V and a conversion efficiency of 1.34 % were obtained under an illumination of 100 mw/cm2.展开更多
Repressing the thermal decomposition during the process of heat treatment plays an indispensable part in the preparation of perovskite films.Here,a methylammonium iodide healing method was applied to prevent the volat...Repressing the thermal decomposition during the process of heat treatment plays an indispensable part in the preparation of perovskite films.Here,a methylammonium iodide healing method was applied to prevent the volatilization of the organic component inside the perovskite structure during the heat treatment.High-quality CH_(3)NH_(3)PbI_(3) film with a much larger grain size over 800 nm was successfully fabricated via this healing method.Besides,the absorption and photoluminescence intensity were also both improved.Finally,the best power conversion efficiency of 18.89%with a fill factor over 80%was realized in an n-i-p configuration while possessing outstanding stability.This work suggests that methylammonium iodide healing method is a reliable way to promote crystal growth and improve the photovoltaic performance and humidity stability of the CH_(3)NH_(3)PbI_(3) solar cells.展开更多
Stretchable organic solar cells(OSCs)have great potential as power sources for the next-generation wearable electronics.Although blending rigid photovoltaic components with soft insulating materials can easily endow t...Stretchable organic solar cells(OSCs)have great potential as power sources for the next-generation wearable electronics.Although blending rigid photovoltaic components with soft insulating materials can easily endow the mechanical ductility of active layers,the photovoltaic efficiencies usually drops in the resulting OSCs.Herein,a high photovoltaic efficiency of 15.03%and a large crack-onset strain of 15.70%is simultaneously achieved based on a ternary blend consisting of polymer donor poly[(2,6-(4,8-bis(5-(2-ethylhexyl-3-fluoro)thiophen-2-yl)-benzo[1,2-b:4,5-b']dithiophene))-alt-(5,5-(1',3'-di-2-thienyl-5',7'-bis(2-ethylhexyl)benzo[1',2'-c:4',5'-c']dithiophene-4,8-dione))](PM6),non-fullerene accepter 2,2'-((2Z,2'Z)-((12,13-bis(2-ethylhexyl)-3,9-diundecyl-12,13-dihydro-[1,2,5]thiadiazolo[3,4-e]thieno[2",3":4',5']thieno[2',3':4,5]pyrrolo[3,2-g]thieno[2',3':4,5]thieno[3,2-b]indole-2,10-diyl)bis(methanylylidene))bis(5,6-difluoro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile(Y6),and soft elastomer polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene(SEBS)through the control of phase separation and crystallization.By employing a high-boiling point solvent additive 1-chloronaphthalene(CN)with different solubilities for PM6 and Y6,the aggregation dynamics of PM6 and Y6 as well as the film solidification process are dramatically altered,allowing for the different molecular rearrangement and liquid-liquid phase separation evolution.Consequently,the ternary film with optimal CN content presents decreased SEBS domains and moderately improved molecular ordering of PM6 and Y6,enabling effective mechanical deformation and charge generation/transport.The revealed corrections between the film-formation process,film microstructure,and photovoltaic/mechanical characteristics in the ternary blend provide deep understanding of the morphology control toward high-performance stretchable OSCs.展开更多
Bulk heterojunction(BHJ) solar cells based on small molecules have attracted potential attention due to their promise of conveniently defined structures, high absorption coefficients, solution process-ability and easy...Bulk heterojunction(BHJ) solar cells based on small molecules have attracted potential attention due to their promise of conveniently defined structures, high absorption coefficients, solution process-ability and easy fabrication. Three D—A—D—A type organic semiconductors(WS-31,WS-32 and WS-52) are synthesized, based on the indoline donor and benzotriazole auxiliary acceptor core, along with either bare thiophene or rigid cyclopentadithiophene as π bridge, rhodanine or carbonocyanidate as end-group. Their HOMO orbitals are delocalized throughout the whole molecules. Whereas the LUMOs are mainly localized on the acceptor part of structure, which reach up to benzothiadiazole, but no distribution on indoline donor. The first excitations for WS-31 and WS-32 are mainly originated by electron transition from HOMO to LUMO level, while for WS-52, partly related to transition between HOMO and LUMO+1 level. The small organic molecules are applied as donor components in bulk heterojunction(BHJ) organic solar cells, using PC_(61)BM as acceptor material to check their photovoltaic performances. The BHJ solar cells based on blended layer of WS-31:PC_(61)BM and WS-32:PC_(61)BM processed with chloroform show overall photoelectric conversion efficiency(PCE) of 0.56% and 1.02%, respectively. WS-32 based BHJ solar cells show a higher current density originated by its relatively larger driving force of photo-induced carrier in photo-active layer to LUMO of PC_(61)BM.展开更多
基金supported by NSFC for Creative Research Groups(21421004) and Distinguished Young Scholars(21325625),NSFC/ChinaOriental Scholarship+4 种基金Fundamental Research Funds for the Central Universities(WJ1416005 and WJ1315025)Scientific Committee of Shanghai(14ZR1409700and 15XD1501400)Programme of Introducing Talents of Discipline to Universities(B16017)Science Foundation for the Excellent Youth Scholars of Hebei Education Department(Y2012017)Science Foundation for Oversea Scholars of Hebei(C201400324)
文摘Cosensitization based on two or multiple dyes as "dye cocktails" can hit the target on compensating and broadening light-harvesting region.Two indoline D-A-π-A motif sensitizers(WS-2 and WS-39) that possess similar light response area but distinctly reversed feature in photovoltaic performance are selected as the specific cosensitization couple. That is, WS-2 shows quite high photocurrent but low photovoltage, and WS-39 gives relatively low photocurrent but quite high photo voltage. Due to the obvious "barrel effect",both dyes show medium PCE around8.50%. In contrast with the previous cosensitization strategy mostly focused on the compensation of light response region, herein we perform different cosensitization sequence, for taking insight into the balance of photocurrent and photo voltage, and achieving the synergistic improvement in power conversion efficiency(PCE). Electronic impedance spectra(EIS) indicate that exploiting dye WS-39 with high V_(OC) value as the primary sensitizer can repress the charge recombination more effectively, resulting in superior V_(OC) rather than using dye WS-2 with high J_(SC)as the primary sensitizer. As a consequence, a high PCE value of 9.48% is obtained with the delicate cosensitization using WS-39 as primary dye and WS-2 as accessory dye, which is higher than the corresponding devices sensitized by each individual dye(around 8.48-8.67%). It provides an effective optimizing strategy of cosensitization how to combine the individual dye advantages for developing highly efficient solar cells.
基金supported by the National Natural Science Foundation of China(NSFC,Nos.51973169,51703172)the Open Project Program of Wuhan National Laboratory for Optoelectronics(No.2020WNLOKF015)the Science Foundation of Wuhan Institute of Technology(No.K202025).
文摘Small-molecule organic solar cells(SMOSCs)have attracted considerable attention owing to the merits of small molecules,such as easy purification,well-defined chemical structure.To achieve high-performance SMOSCs,the rational design of well-matched donor and acceptor materials is extremely essential.In this work,two new small molecular donor materials with subtle change in the conjugated side thiophene rings are synthesized.The subtle change significantly affects the photovoltaic performance of molecular donors.Compared with chlorinated molecule MDJ-Cl,the non-chlorinated analogue MDJ exhibits decreased miscibility with the non-fullerene acceptor Y6,can more efficiently quench the excitons of Y6.As a result,a improved PCE of 11.16% is obtained for MDJ:Y6 based SMOSCs.The results highlight the importance of fine-tuning the molecular structure to achieve high-performance SMOSCs.
基金supported by Natural Science Foundation of Zhejiang Province(Nos.LQ23E030002,LZ23B040001)the National Natural Science Foundation of China(Nos.52303226,21971049)L.Zhan acknowledges the research start-up fund from Hangzhou Normal University(4095C50222204002).
文摘Organic photovoltaics(OPVs)have achieved remarkable progress,with laboratory-scale single-junction devices now demonstrating power conversion efficiencies(PCEs)exceeding 20%.However,these efficiencies are highly dependent on the thickness of the photoactive layer,which is typically around 100 nm.This sensitivity poses a challenge for industrial-scale fabrication.Achieving high PCEs in thick-film OPVs is therefore essential.This review systematically examines recent advancements in thick-film OPVs,focusing on the fundamental mechanisms that lead to efficiency loss and strategies to enhance performance.We provide a comprehensive analysis spanning the complete photovoltaic process chain:from initial exciton generation and diffusion dynamics,through dissociation mechanisms,to subsequent charge-carrier transport,balance optimization,and final collection efficiency.Particular emphasis is placed on cutting-edge solutions in molecular engineering and device architecture optimization.By synthesizing these interdisciplinary approaches and investigating the potential contributions in stability,cost,and machine learning aspects,this work establishes comprehensive guidelines for designing high-performance OPVs devices with minimal thickness dependence,ultimately aiming to bridge the gap between laboratory achievements and industrial manufacturing requirements.
基金supported by the National High Technology Research and Development of China(863 Program)(2009AA03Z217)the National Natural Science Foundation of China(90922028)the Natural Science Foundation of Huaqiao University(09BS401)
文摘N-cetylpyridinium iodide(N-CPI)as a new electric additive for enhancing photovoltaic performance of the dye-sensitized solar cell(DSSC)was studied.It showed high efficiency for enhancing both the open-circuit voltage and the short-circuit current density of DSSC when the suitable amount of N-CPI as 0.02 M was added in liquid electrolyte.The energy conversion effi-ciency of DSSC increased from 4.429%to 6.535%,with 47.55%enhancement.Therefore,it is a highly efficient electric addi-tive for DSSC.The intrinsic reason is owing to the special molecular structure of N-CPI,which contains two different polarity groups.As a surfactant,N-CPI could form ordered arrangement in liquid electrolyte,which affects the diffusing ability and the redox reaction of I-/I3-,and further affects the photovoltaic performance of DSSC.
基金supported by the National Natural Science Foundation of China(U1401244,21374025,21372053,21572041,51503050)the Key Laboratory of Nanosystem and Hierarchical Fabrication(CAS)+2 种基金State Key Laboratory of Luminescent Materials and Devices(2016-skllmd-05)Youth Association for Promoting Innovation(CAS)Center for Excellence in Nanoscience(CAS)
文摘Three model polythiophenes,PTCBT,PTCFBT and PFTCBT,have been synthesized to investigate the effect of fluorination on photovoltaic performance of polythiothenes.Compared with PTCBT,PFTCBT with F atom on TC unit shows a narrower optical bandgap(1.79 eV),higher crystallinity,and ideal morphology in the active layer,leading to a higher short-circuit current density(J_(SC))of 11.84 mA/cm^2 and a power conversion efficiency(PCE)of 5.93%.The lock-up function of fluorine enhances polythiophene backbone planarity and molecular packing.
基金supported by the National Natural Science Foundation of China(Nos.52303226,21971049)Zhejiang Provincial Natural Science Foundation(Nos.LQ23E030002,LZ23B040001)“Ten-thousand Talents Plan”of Zhejiang Province(No.2019R52040)。
文摘The microstructure of the active layer in organic photovoltaics(OPVs),such as the size of phase separation,purity of the phases,and molecular packing within each phase,plays a crucial role in influencing the behavior of excitons and charge carriers within the active layer.It is also a key determinant of the photovoltaic performance of the device.During the optimization of OPV devices,the use of additives has been demonstrated to be an effective strategy in microstructure control,leading to enhanced performance.Therefore,the quest for stable and efficient novel additives,along with an exploration and summarization of the mechanisms underlying additive-induced microstructure control,is essential for a better understanding of the developmental trends of high-performance additives.In this review,we categorize additives based on their chemical structures and discuss their effects on the microstructure of the active layer from both thermodynamic and kinetic perspectives.Furthermore,we elaborate on the working mechanisms and their impact on the photovoltaic performance of the devices.This review provides an overview of recent advances in additives for OPVs,offering potential guidance for the future development of additives and further optimization of the active layer in photovoltaic devices.
基金supported by the Scientific Research Project of Tianjin Municipal Education Committee(2017KJ261)。
文摘Hole-transporting materials play a vital role in terms of the performance of perovskite solar cells(PSCs).The dithieno[3,2-b:2’,3’-d]pyrrole(DTP),an S,N-heterocyclic building block,has been proved to be desirable for molecular design of hole-transporting materials in PSCs.We developed an asymmetrically substituted DTP small-molecule(JW12)and a reference compound(JW11).The asymmetrical structure of JW12 leads to different absorption properties and electron distribution.The device in a planar n-i-p architecture using JW12 shows a much higher PCE(18.07%)than that based on JW11(15.46%),which is also better than the device based on spiro-OMe TAD(17.47%).We hope our research can provide a new perspective in molecular design of organic HTMs for perovskite solar cells.
基金supported by the National Natural Science Foundation of China(No.21373132,No.21603133)the Education Department of Shaanxi Provincial Government Research Projects(No.16JK1142,No.16JK1134)the Scientific Research Foundation of Shaanxi University of Technology for Recruited Talents(No.SLGKYQD2-13,No.SLGKYQD2-10,No.SLGQD14-10)
文摘In this work,the photovoltaic properties of BFBPD-PC61 BM system as a promising high-performance organic solar cell（OSC） were theoretically investigated by means of quantum chemistry and molecular dynamics calculations coupled with the incoherent charge-hopping model.Moreover,the hole carrier mobility of BFBPD thin-film was also estimated with the aid of an amorphous cell including 100 BFBPD molecules.Results revealed that the BFBPD-PC61 BM system possesses a middle-sized open-circuit voltage of 0.70 V,large short-circuit current density of 17.26 mA ·cm^-2,high fill factor of 0.846,and power conversion efficiency of 10%.With the Marcus model,in the BFBPD-PC61 BM interface,the exciton-dissociation rate,kdis,was predicted to be 2.684×10^13 s^-1,which is as 3-5 orders of magnitude large as the decay（radiative and non-radiative） one（10-8-10^10s^-1）,indicating a high exciton-dissociation efficiency of 100% in the BFBPD-PC61 BM interface.Furthermore,by the molecular dynamics simulation,the hole mobility of BFBPD thin-film was predicted to be as high as 1.265 × 10^-2 cm-2·V^-1·s^-1,which can be attributed to its dense packing in solid state.
基金the National Natural Science Foundation of China (22175180, 21975260)。
文摘Lead-based organic-inorganic hybrid perovskites have exhibited great potential in photovoltaics,achieving power conversion efficiencies(PCEs) exceeding 25%.However,the toxicity of lead and the instability of these materials under moist conditions pose significant barriers to large-scale production.To overcome these limitations,researchers have proposed mixed-valence double perovskites,where Cs_(2)Au~ⅠAu~ⅢI_6 is a particularly effective absorber due to its suitable band gap and high absorptance efficiency.To further extend the scope of these lead-free materials,we varied the trivalent gold ion and halogen anion in Cs_(2)Au~ⅠAu~ⅢI_6,resulting in 18 new structures with unique properties.Further,using first-principles calculations and elimination criteria,we identified four materials with ideal band gaps,small effective carrier mass,and strong anisotropic optical properties.According to theoretical modeling,Cs_(2)AuSbCl_6,Cs_(2)AuInCl_6,and Cs_(2)AuBiCl_6 are potential candidates for solar cell absorbers,with a spectroscopic limited maximum efficiency(SLME) of approximately 30% in a 0.25 μm-thick film.These three compounds have not been previously reported,and therefore,our work provides new insights into potential materials for solar energy conversion.We aim for this theoretical exploration of novel perovskites to guide future experiments and accelerate the development of high-performance photovoltaic devices.
基金Funded by the National Natural Science Foundation of China(Nos.20674022,20774031,21074039)the Natural Science Foundation of Guangdong(Nos.2006A10702003,2009B090300025,2010A090100001,2014A030313241,2014B090901068,2016A010103003)+1 种基金the Science and Technology Program of Guangdong and GuangzhouThe Ministry of Education of the People’s Republic of China(No.20090172110011)
文摘The porphyrin derivatives, 5,10,15,20-tetra（4-（N-pentane-carboxamide） phenyl） porphyrin（4 NC5-TPP）, 5,10,15,20-tetra（4-（N-dodecane-carboxamide） phenyl） porphyrin（4 NC12-TPP） and their zinc-complexes（4 NC5-TPPZn and 4 NC12-TPPZn）, have been synthesized. Their thermal properties and morphologies were investigated via thermal gravity analysis（TGA）, differential scanning calorimetry（DSC） and polarized optical microscopy（POM）. It was found that the 4 NC5-TPP was amorphous and the 4 NC5-TPPZn was crystalline at room temperature, while the 4 NC12-TPP formed the columnar liquid crystal and the 4 NC12-TPPZn showed the spherulite texture. The electron state density distributions and the optimum configuration of the porphyrin derivatives were calculated by chemical simulation. The electrochemical oxidation and reduction abilities of the porphyrin derivatives were studied by cyclic voltammetry（CV）. It was indicated that the porphyrin derivatives had the potential to develop organic photovoltaic（OPV） devices. Using the porphyrin derivatives as donor materials and the 3,4,9,10-perylenetetracarboxylic dianhydride（PTCDA） as the acceptor material, the OPV devices were fabricated. The device structure is ITO/porphyrin derivatives：PTCDA/Al. The relationship between the morphology and performance of OPV was studied. It was found that the crystalline morphology of the film was beneficial to improve the efficiency of the devices.
基金Project(2012FU125X03)supported by Open Research Fund Project of National Engineering Research Center of SeafoodChina+3 种基金Project(2011–191)supported by the Key Science and Technology Platform of Liaoning Provincial Education DepartmentChinaProject(2010–354)supported by the Science and Technology Platform of DalianChina
文摘Ho^3＋-doped titanium dioxide（TiO2：Ho^3＋） downconversion（DC） nanowires were synthesized through a simple hydrothermal method followed by a subsequent calcination process after being immersed in Ho（NO3）3 aqueous solution. Moreover, TiO2：Ho^3＋ nanowires（HTNWs） were used as the photoanode in dye-sensitized solar cells（DSSCs） to investigate their photoelectric properties. Scanning electron microscopy（SEM） and X-ray diffraction（XRD） were used to characterize the morphology and structure of the material, respectively. The photofluorescence and ultraviolet-visible absorption spectra of HTNWs reveal a DC from the near and middle ultraviolet light to visible light which matches the strong absorbed region of the N719 dye. Compared with the pure TNW photoanode, HTNWs DC photoanodes show greater photovoltaic efficiency. The photovoltaic conversion efficiency（η） of the DSSCs with HTNWs photoanode doped with 4% Ho2O3（mass fraction） is two times that with pure TNW photoanode. This enhancement could be attributed to HTNWs which could extend the spectral response range of DSSCs to the near and middle ultraviolet region and increase the short-circuit current density（Jsc） of DSSCs, thus leading to the enhancement of photovoltaic conversion efficiency.
基金sponsored by Guangzhou Basic and Applied Basic Research Foundation(No.303523)。
文摘The commercialized poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)is usually used as hole transport layers(HTLs)in tin-based perovskite solar cells(TPSCs).However,the further development has been restricted due to the acidity that could damage the stability of TPSCs.Although the PEDOT:PSS solution can be diluted by water to decrease acidity and reduce the cost of device fabrication,the electrical conductivity will decrease obviously in diluted PEDOT:PSS solution.Herein,potassium thiocyanate(KSCN)is selected to regulate the properties of PEDOT:PSS HTLs from the diluted PEDOT:PSS aqueous solution by water with a volume ratio of 1:1 to prepare efficient TPSCs.The effect of KSCN addition on the structure and photoelectrical properties of PEDOT:PSS HTLs and TPSCs have been systematically studied.At the optimal KSCN concentration,the TPSCs based on KSCN-doped PEDOT:PSS HTLs(KSCN-PSCs)demonstrate the champion power conversion efficiency(PCE)of 8.39%,while the reference TPSCs only show a champioan PCE of 6.70%.The further analysis demonstrates that the KSCN additive increases the electrical conductivity of HTLs prepared by the diluted PEDOT:PSS solution,improves the microstructure of perovskite film,and inhibits carrier recombination in TPSCs,leading to the reduced hysteresis effect and enhanced PCE in KSCN-PSCs.This work gives a low-cost and practical strategy to develop a high-quality PEDOT:PSS HTLs from diluted PEDOT:PSS aqueous solution for efficient TPSCs.
基金supported by the 973 Programs (2011CB935702 and 2009CB623603)the NSF of China(Nos. 20834006, 51003006 and 21161160443)the Fundamental Research Funds for the Central Universities
文摘6,7-Dialkoxy-2,3-diphenylquinoxaline based narrow band gap conjugated polymers, poly[2,7-（9-octyl-9H- carbazole）-alt-5,5-（5,8-di-2-thinenyl-（6,7-dialkoxy-2,3-diphenylquinoxaline））] （PCDTQ） and poly[2,7-（9,9-dioctylfluorene）- alt-5,5-（5,8-di-2-thinenyl-（6,7-dialkoxy-2,3-diphenylquinoxaline））] （PFDTQ）, have been synthesized by Suzuki polycondensation. Their optical, electrochemical, transport and photovoltaic properties have been investigated in detail. Hole mobilities of PCDTQ and PFDTQ films spin coated from 1,2-dichlorobenzene （DCB） solutions are 1.0 X 10-4 and 4.1 X 10-4 cm2 V-1 s-l, respectively. Polymer solar cells were fabricated with the as-synthesized polymers as the donor and PC61BM and PC7 IBM as the acceptor. Devices based on PCDTQ：PC71BM （1：3） and PFDTQ：PC7 IBM （1：3） fabricated from DCB solutions demonstrated a power conversion efficiency （PCE） of 2.5% with a Voc of 0.95 V and a PCE of 2.5% with a Voof 0.98 V, respectively, indicating they are promising donor materials.
基金supported by National Research Fund for High-Tech Research and Development of China Program(No. 2007AA05Z439)
文摘The pure TiO2 and Fe salts [Fe（C2O4）3,5H2O]-doped TiO2 electrodes were prepared by the hydrothermal method. The pure TiO2 or Fe-doped TiO2 slurry was coated onto the fluorine-doped tin oxide glass substrate by the Doctor Blade method and then sintered at 450 ℃. The Mott-Schottks, plot indicates that the fiat band potential of TiO2 was shifted positively after Fe-doped TiO2. The positive shift of the fiat band potential improves the driving force of injected electrons from the LUMO of the dye to the conduction band of TiO2. This study shows that photovoltaic efficiency increased by 22.9% from 6.07% to 7.46% compared to pure TiO2, and the fill factors increased from 0.53 to 0.63.
基金Project supported by the Graduate Student Education Teaching Reform Project,China(Grant No.JG201512)the Young Teachers Research Project of Yanshan University,China(Grant No.13LGB028)
文摘According to the good charge transporting property of perovskite, we design and simulate a p–i–n-type all-perovskite solar cell by using one-dimensional device simulator. The perovskite charge transporting layers and the perovskite absorber constitute the all-perovskite cell. By modulating the cell parameters, such as layer thickness values, doping concentrations and energy bands of n-, i-, and p-type perovskite layers, the all-perovskite solar cell obtains a high power conversion efficiency of 25.84%. The band matched cell shows appreciably improved performance with widen absorption spectrum and lowered recombination rate, so weobtain a high J_（sc） of 32.47 m A/cm^2. The small series resistance of the all-perovskite solar cell also benefits the high J_（sc）. The simulation provides a novel thought of designing perovskite solar cells with simple producing process, low production cost and high efficient structure to solve the energy problem.
基金National Natural Science Foundation of China (No. 21176223)National Natural Science Foundation of China (No. 21406202)Natural Science Foundation of Zhejiang province (No. LY15B020009)
文摘Three novel triarylamine dyes（AFL1-AFL3） containing fluorenyl and the biphenyl moieties have been designed and synthesized for application in dye-sensitized solar cells.The light-harvesting capabilities and photovoltaic performance of these dyes were investigated systematically through comparison of different π-bridges.The dye with a furan linker exhibited a higher open-circuit voltage（VOC） and monochromatic incident photon-to-current conversion efficiency（IPCE） compared to thiophene and benzene linker.Thus,AFL3 containing a furan linker exhibited the maximum overall conversion efficiency of 5.81%（VOC = 760 mV,JSC = 11.36 mA cm^-2 and ff=0.68） under standard global AM 1.5 G solar condition.
基金National Natural Science Foundation of China(No.11174071)the International Cooperation Project of Wuhan City and Hubei Province(Nos.201070934339 and 2010BFA010)
文摘CdSe/CdS semiconductor quantum dots co-sensitized TiO2 nanorod array was fabricated on the transparent conductive fluorine-doped tin oxide （FTO） substrate using the hydrothermal and successive ionic layer adsorption and reaction （SILAR） process. The structural and morphological properties of the samples were characterized by X-ray diffraction （XRD）, field-emission scanning electron microscopy （FESEM）, and transmission electron microscopy （TEM）. The results indicate that CdSe/CdS QDs are uniformly coated on the surface of the TiO2 nanorods. The shift of light absorption edge was monitored by taking UV-visible absorption spectra. Compared with the absorption spectra of the TiO2 nanorod array, deposition of CdSe/CdS QDs shifts the absorption edge to the higher wavelength. The enhanced light absorption in the visible-light region of CdSe/CdS/TiO2 nanorod array indicates that CdSe/CdS layers can act as co-sensitizers in quantum dots sensitized solar cells （QDSSCs）. By optimizing the CdSe layer deposition cycles, a photocurrent of 5.78 mA/cm2, an open circuit photovoltage of 0.469 V and a conversion efficiency of 1.34 % were obtained under an illumination of 100 mw/cm2.
基金This work was fianancially supported by the National Key R&D Program of China(Grant No.2019YFB1503200)。
文摘Repressing the thermal decomposition during the process of heat treatment plays an indispensable part in the preparation of perovskite films.Here,a methylammonium iodide healing method was applied to prevent the volatilization of the organic component inside the perovskite structure during the heat treatment.High-quality CH_(3)NH_(3)PbI_(3) film with a much larger grain size over 800 nm was successfully fabricated via this healing method.Besides,the absorption and photoluminescence intensity were also both improved.Finally,the best power conversion efficiency of 18.89%with a fill factor over 80%was realized in an n-i-p configuration while possessing outstanding stability.This work suggests that methylammonium iodide healing method is a reliable way to promote crystal growth and improve the photovoltaic performance and humidity stability of the CH_(3)NH_(3)PbI_(3) solar cells.
基金supported by the National Natural Science Foundation of China(51873204 and 51933010)the 111 Project(B21005)+3 种基金the National 1000-talent-plan program(1110010341)the Science and Technology Program of Shaanxi Province(2021KJXX-13)the Fundamental Research Funds for the Central Universities(GK202103104)supported by Open Research Fund of State Key Laboratory of Polymer Physics and Chemistry,Changchun Institute of Applied Chemistry,and Chinese Academy of Sciences.
文摘Stretchable organic solar cells(OSCs)have great potential as power sources for the next-generation wearable electronics.Although blending rigid photovoltaic components with soft insulating materials can easily endow the mechanical ductility of active layers,the photovoltaic efficiencies usually drops in the resulting OSCs.Herein,a high photovoltaic efficiency of 15.03%and a large crack-onset strain of 15.70%is simultaneously achieved based on a ternary blend consisting of polymer donor poly[(2,6-(4,8-bis(5-(2-ethylhexyl-3-fluoro)thiophen-2-yl)-benzo[1,2-b:4,5-b']dithiophene))-alt-(5,5-(1',3'-di-2-thienyl-5',7'-bis(2-ethylhexyl)benzo[1',2'-c:4',5'-c']dithiophene-4,8-dione))](PM6),non-fullerene accepter 2,2'-((2Z,2'Z)-((12,13-bis(2-ethylhexyl)-3,9-diundecyl-12,13-dihydro-[1,2,5]thiadiazolo[3,4-e]thieno[2",3":4',5']thieno[2',3':4,5]pyrrolo[3,2-g]thieno[2',3':4,5]thieno[3,2-b]indole-2,10-diyl)bis(methanylylidene))bis(5,6-difluoro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile(Y6),and soft elastomer polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene(SEBS)through the control of phase separation and crystallization.By employing a high-boiling point solvent additive 1-chloronaphthalene(CN)with different solubilities for PM6 and Y6,the aggregation dynamics of PM6 and Y6 as well as the film solidification process are dramatically altered,allowing for the different molecular rearrangement and liquid-liquid phase separation evolution.Consequently,the ternary film with optimal CN content presents decreased SEBS domains and moderately improved molecular ordering of PM6 and Y6,enabling effective mechanical deformation and charge generation/transport.The revealed corrections between the film-formation process,film microstructure,and photovoltaic/mechanical characteristics in the ternary blend provide deep understanding of the morphology control toward high-performance stretchable OSCs.
基金supported by the NSFC for Creative Research Groups(21421004)Distinguished Young Scholars(21325625)+4 种基金NSFC/China,Science and Technology Commission of Shanghai Municipality(14YF1410500 and 15XD1501400)Shanghai Young Teacher Supporting Foundation(ZZEGD14011)Program for Professor of Special Appointment(Eastern Scholar)"Shu Guang" project supported by Shanghai Municipal Education Commission and Shanghai Education Development Foundation(13SG55)Grants of computing timeat the C3SE supercomputing Center at Chalmers(Gteborg)
文摘Bulk heterojunction(BHJ) solar cells based on small molecules have attracted potential attention due to their promise of conveniently defined structures, high absorption coefficients, solution process-ability and easy fabrication. Three D—A—D—A type organic semiconductors(WS-31,WS-32 and WS-52) are synthesized, based on the indoline donor and benzotriazole auxiliary acceptor core, along with either bare thiophene or rigid cyclopentadithiophene as π bridge, rhodanine or carbonocyanidate as end-group. Their HOMO orbitals are delocalized throughout the whole molecules. Whereas the LUMOs are mainly localized on the acceptor part of structure, which reach up to benzothiadiazole, but no distribution on indoline donor. The first excitations for WS-31 and WS-32 are mainly originated by electron transition from HOMO to LUMO level, while for WS-52, partly related to transition between HOMO and LUMO+1 level. The small organic molecules are applied as donor components in bulk heterojunction(BHJ) organic solar cells, using PC_(61)BM as acceptor material to check their photovoltaic performances. The BHJ solar cells based on blended layer of WS-31:PC_(61)BM and WS-32:PC_(61)BM processed with chloroform show overall photoelectric conversion efficiency(PCE) of 0.56% and 1.02%, respectively. WS-32 based BHJ solar cells show a higher current density originated by its relatively larger driving force of photo-induced carrier in photo-active layer to LUMO of PC_(61)BM.
