Lead halide hybrid perovskites(LHP)have emerged as one of the most promising photovoltaic materials for their remarkable solar energy conversion ability.The transportation of the photoinduced carriers in LHP could scr...Lead halide hybrid perovskites(LHP)have emerged as one of the most promising photovoltaic materials for their remarkable solar energy conversion ability.The transportation of the photoinduced carriers in LHP could screen the defect recombination with the help of the large polaron formation.However,the physical insight of the relationship between the superior optical-electronic performance of perovskite and its polaron dynamics related to the electron-lattice strong coupling induced by the substitution engineering is still lack of investigation.Here,the bandgap modulated thin films ofα-FAPbI_(3)with different element substitution is investigated by the time resolved Terahertz spectroscopy.We find the polaron recombination dynamics could be prolonged in LHP with a relatively smaller bandgap,even though the formation of polaron will not be affected apparently.Intuitively,the large polaron mobility in(FAPb I_(3))0.95(MAPbI_(3))0.05thin film is~30%larger than that in(FAPb I_(3))0.85(MAPbBr_(3))0.15.The larger mobility in(FAPb I_(3))0.95(MAPb I_(3))0.05could be assigned to the slowing down of the carrier scattering time.Therefore,the physical origin of the higher carrier mobility in the(FAPb I_(3))0.95(MAPbI_(3))0.05should be related with the lattice distortion and enhanced electron–phonon coupling induced by the substitution.In addition,(FAPbI_(3))0.95(MAPbI_(3))0.05will lose fewer active carriers during the polaron cooling process than that in(FAPb I_(3))0.85(MAPbBr_(3)),indicating lower thermal dissipation in(FAPbI_(3))0.95(MAPbI_(3))0.05.Our results suggest that besides the smaller bandgap,the higher polaron mobility improved by the substitution engineering inα-FAPbI_(3)can also be an important factor for the high PCE of the black phaseα-FAPbI_(3)based solar cell devices.展开更多
Perovskite solar cells(PSCs)have witnessed great achievement in the past decade.Most of previous researches focus on the n-i-p structure of PSCs with ultra-high efficiency.While the n-i-p devices usually used the unst...Perovskite solar cells(PSCs)have witnessed great achievement in the past decade.Most of previous researches focus on the n-i-p structure of PSCs with ultra-high efficiency.While the n-i-p devices usually used the unstable charge transport layers,such as the hygroscopic doped spiro-OMe TAD,which affect the long-term stability.The inverted device with the p-i-n structure owns better stability when using stable undoped organic molecular or metal oxide materials.There are significant progresses in inverted PSCs,most of them related to charge transport or interface engineering.In this review,we will mainly summarize the inverted PSCs progresses related to the interface engineering.After that,we prospect the future direction on inverted PSCs.展开更多
基金supported by the National Natural Science Foundation of China(Nos.92050203,61905264,61925507,61875211,61674023,62005296,and 62105347)the National Key R&D Program of China 2017YFE0123700+1 种基金Shanghai Pilot Program for Basic Research(22JC1403200)the CAS Interdisciplinary Innovation Team。
文摘Lead halide hybrid perovskites(LHP)have emerged as one of the most promising photovoltaic materials for their remarkable solar energy conversion ability.The transportation of the photoinduced carriers in LHP could screen the defect recombination with the help of the large polaron formation.However,the physical insight of the relationship between the superior optical-electronic performance of perovskite and its polaron dynamics related to the electron-lattice strong coupling induced by the substitution engineering is still lack of investigation.Here,the bandgap modulated thin films ofα-FAPbI_(3)with different element substitution is investigated by the time resolved Terahertz spectroscopy.We find the polaron recombination dynamics could be prolonged in LHP with a relatively smaller bandgap,even though the formation of polaron will not be affected apparently.Intuitively,the large polaron mobility in(FAPb I_(3))0.95(MAPbI_(3))0.05thin film is~30%larger than that in(FAPb I_(3))0.85(MAPbBr_(3))0.15.The larger mobility in(FAPb I_(3))0.95(MAPb I_(3))0.05could be assigned to the slowing down of the carrier scattering time.Therefore,the physical origin of the higher carrier mobility in the(FAPb I_(3))0.95(MAPbI_(3))0.05should be related with the lattice distortion and enhanced electron–phonon coupling induced by the substitution.In addition,(FAPbI_(3))0.95(MAPbI_(3))0.05will lose fewer active carriers during the polaron cooling process than that in(FAPb I_(3))0.85(MAPbBr_(3)),indicating lower thermal dissipation in(FAPbI_(3))0.95(MAPbI_(3))0.05.Our results suggest that besides the smaller bandgap,the higher polaron mobility improved by the substitution engineering inα-FAPbI_(3)can also be an important factor for the high PCE of the black phaseα-FAPbI_(3)based solar cell devices.
基金supported by the National Natural Science Foundation of China(Grant No.61925405)the National Key Research and Development Program of China(Grant No.2020YFB1506400)。
文摘Perovskite solar cells(PSCs)have witnessed great achievement in the past decade.Most of previous researches focus on the n-i-p structure of PSCs with ultra-high efficiency.While the n-i-p devices usually used the unstable charge transport layers,such as the hygroscopic doped spiro-OMe TAD,which affect the long-term stability.The inverted device with the p-i-n structure owns better stability when using stable undoped organic molecular or metal oxide materials.There are significant progresses in inverted PSCs,most of them related to charge transport or interface engineering.In this review,we will mainly summarize the inverted PSCs progresses related to the interface engineering.After that,we prospect the future direction on inverted PSCs.
