Carbazole moiety-based 2PACz([2-(9H-carbazol-9-yl)ethyl]phosphonic acid)self-assembled monolayers(SAMs)are excellent hole-selective contact(HSC)materials with abilities to excel the charge-transferdynamics of perovski...Carbazole moiety-based 2PACz([2-(9H-carbazol-9-yl)ethyl]phosphonic acid)self-assembled monolayers(SAMs)are excellent hole-selective contact(HSC)materials with abilities to excel the charge-transferdynamics of perovskite solar cells(PSCs).Herein,we report a facile but powerful method to functionalize the surface of 2PACz-SAM,by which reproducible,highly stable,high-efficiency wide-bandgap PSCs can be obtained.The 2PACz surface treatment with various donor number solvents improves assembly of 2PACz-SAM and leave residual surface-bound solvent molecules on 2PACz-SAM,which increases perovskite grain size,retards halide segregation,and accelerates hole extraction.The surface functionalization achieves a high power conversion efficiency(PCE)of 17.62%for a single-junction wide-bandgap(~1.77 e V)PSC.We also demonstrate a monolithic all-perovskite tandem solar cell using surfaceengineered HSC,showing high PCE of 24.66%with large open-circuit voltage of 2.008 V and high fillfactor of 81.45%.Our results suggest this simple approach can further improve the tandem device,when coupled with a high-performance narrow-bandgap sub-cell.展开更多
Mixed tin-ead perovskites suffer from structural instability and rapid tin oxidation;thus,the investigation of their optimal composition ranges is important to address these inherent weaknesses.The critical role of tr...Mixed tin-ead perovskites suffer from structural instability and rapid tin oxidation;thus,the investigation of their optimal composition ranges is important to address these inherent weaknesses.The critical role of triple cations in mixed Sn–Pb iodides is studied by performing a wide range of compositional screenings over mechanochemically synthesized bulk and solution-processed thin films.A ternary phase map of FA(Sn_(0.6)Pb_(0.4))I_(3),MA(Sn_(0.6)Pb_(0.4))I_(3),and Cs(Sn_(0.6)Pb_(0.4))I_(3)is formed,and a promising composition window of(FA_(0.6-x)MA_(0.4)Cs_(x))Sn_(0.6)Pb_(0.4)I_(3)(0≤x≤0.1)is demonstrated through phase,photoluminescence,and stability evaluations.Solar cell performance and chemical stability across the targeted compositional space are investigated,and FA_(0.55)MA_(0.4)Cs_(0.05)Sn_(0.6)Pb_(0.4)I_(3)with strain-relaxed lattices,reduced defect densities,and improved oxidation stability is demonstrated.The inverted perovskite solar cells with the optimal composition demonstrate a power conversion efficiency of over 22%with an open-circuit voltage of 0.867 V,which corresponds to voltage loss of 0.363 V,promising for the development of narrow-bandgap perovskite solar cells.展开更多
Blue photodetectors(PDs)are attracting great attention for various applications.Commercial blue PDs based on inorganic GaP or InGaN absorbers are limited by their expensive,complex,and high-temperature fabrication tec...Blue photodetectors(PDs)are attracting great attention for various applications.Commercial blue PDs based on inorganic GaP or InGaN absorbers are limited by their expensive,complex,and high-temperature fabrication techniques.Organic absorber-based blue PDs still have much lower photode-tecting properties than inorganic blue PDs.In this study,a high-performance self-powered blue PD is developed using methylammonium lead halide(MAPbX_(3);X=I,Br,and Cl)perovskites based on the eco-nomic and facile solution process at low temperatures.Optimal composition is obtained through halide-composition engineering.Our best-performing device exhibits an average external quantum efficiency and an average detectivity of 42.7%and 8.65×10^(11) Jones,respectively,within the blue region.The peak responsivity of the proposed PD is 0.174 A W^(−1) at 455 nm,which is comparable to that of commercial gallium phosphide blue PD(0.180 A W^(−1) at 470 nm).Moreover,the proposed device exhibits excellent environmental stability under ambient air conditions.These findings will act as a basis for next-generation image sensor technologies,such as vertically stacked red/green/blue PDs.展开更多
基金supported by the National Research Foundation of Korea (NRF)the Ministry of Science,ICT (2022M3J1A1085285,2019R1A2C1084010,and 2022R1A2C2006532)the Korea Electric Power Corporation (R20XO02-1)。
文摘Carbazole moiety-based 2PACz([2-(9H-carbazol-9-yl)ethyl]phosphonic acid)self-assembled monolayers(SAMs)are excellent hole-selective contact(HSC)materials with abilities to excel the charge-transferdynamics of perovskite solar cells(PSCs).Herein,we report a facile but powerful method to functionalize the surface of 2PACz-SAM,by which reproducible,highly stable,high-efficiency wide-bandgap PSCs can be obtained.The 2PACz surface treatment with various donor number solvents improves assembly of 2PACz-SAM and leave residual surface-bound solvent molecules on 2PACz-SAM,which increases perovskite grain size,retards halide segregation,and accelerates hole extraction.The surface functionalization achieves a high power conversion efficiency(PCE)of 17.62%for a single-junction wide-bandgap(~1.77 e V)PSC.We also demonstrate a monolithic all-perovskite tandem solar cell using surfaceengineered HSC,showing high PCE of 24.66%with large open-circuit voltage of 2.008 V and high fillfactor of 81.45%.Our results suggest this simple approach can further improve the tandem device,when coupled with a high-performance narrow-bandgap sub-cell.
基金supported by the Korea Electric Power Corporation(Grant number:R20XO02-1)the National Research Foundation of Korea(NRF)funded by the Ministry of Science,ICT(NRF-2019R1A2C1084010).
文摘Mixed tin-ead perovskites suffer from structural instability and rapid tin oxidation;thus,the investigation of their optimal composition ranges is important to address these inherent weaknesses.The critical role of triple cations in mixed Sn–Pb iodides is studied by performing a wide range of compositional screenings over mechanochemically synthesized bulk and solution-processed thin films.A ternary phase map of FA(Sn_(0.6)Pb_(0.4))I_(3),MA(Sn_(0.6)Pb_(0.4))I_(3),and Cs(Sn_(0.6)Pb_(0.4))I_(3)is formed,and a promising composition window of(FA_(0.6-x)MA_(0.4)Cs_(x))Sn_(0.6)Pb_(0.4)I_(3)(0≤x≤0.1)is demonstrated through phase,photoluminescence,and stability evaluations.Solar cell performance and chemical stability across the targeted compositional space are investigated,and FA_(0.55)MA_(0.4)Cs_(0.05)Sn_(0.6)Pb_(0.4)I_(3)with strain-relaxed lattices,reduced defect densities,and improved oxidation stability is demonstrated.The inverted perovskite solar cells with the optimal composition demonstrate a power conversion efficiency of over 22%with an open-circuit voltage of 0.867 V,which corresponds to voltage loss of 0.363 V,promising for the development of narrow-bandgap perovskite solar cells.
基金This work was financially supported by the National Re-search Foundation of Korea(NRF)funded by the Ministry of Science,ICT(Nos.NRF-2019M3D1A2104108,2019R1A2C1084010,2020R1A4A2002161,and 2020R1A6A3A13073172)。
文摘Blue photodetectors(PDs)are attracting great attention for various applications.Commercial blue PDs based on inorganic GaP or InGaN absorbers are limited by their expensive,complex,and high-temperature fabrication techniques.Organic absorber-based blue PDs still have much lower photode-tecting properties than inorganic blue PDs.In this study,a high-performance self-powered blue PD is developed using methylammonium lead halide(MAPbX_(3);X=I,Br,and Cl)perovskites based on the eco-nomic and facile solution process at low temperatures.Optimal composition is obtained through halide-composition engineering.Our best-performing device exhibits an average external quantum efficiency and an average detectivity of 42.7%and 8.65×10^(11) Jones,respectively,within the blue region.The peak responsivity of the proposed PD is 0.174 A W^(−1) at 455 nm,which is comparable to that of commercial gallium phosphide blue PD(0.180 A W^(−1) at 470 nm).Moreover,the proposed device exhibits excellent environmental stability under ambient air conditions.These findings will act as a basis for next-generation image sensor technologies,such as vertically stacked red/green/blue PDs.
