Lead-free double perovskite,Cs2AgBiBr6,with higher stability and lower toxicity than those of its lead counterparts,has been considered a promising alternative for next-generation photovoltaic materials.For practical ...Lead-free double perovskite,Cs2AgBiBr6,with higher stability and lower toxicity than those of its lead counterparts,has been considered a promising alternative for next-generation photovoltaic materials.For practical applications,a facile deposition method that could be used to fabricate high-quality double perovskite films with large grain size is highly desired.However,such kind of facile method has never been established for Cs2AgBiBr6.Herein,high-quality Cs2AgBiBr6thin films with an average grain size of approximately 0.5μm were successfully deposited via a simple onestep spin-coating method by using dimethyl sulfoxide(DMSO)-N,N-dimethylformamide(DMF)mixture with optimized volume ratio as the solvent and chlorobenzene(CB)as the antisolvent.On the basis of satisfactory quality of the film efficient(>1%)Cs2AgBiBr6perovskite solar cells were constructed.Furthermore,the photo-generated charge-carrier transfer from Cs2AgBiBr6to the adjacent carrier extraction layers was systematically investigated via femtosecond transient spectroscopies.This study offers a new pathway to acquiring high-quality Cs2AgBiBr6thin films and provides a useful guide toward the development of high-efficiency double perovskite solar cells in the future.展开更多
Organic-inorganic hybrid two-dimensional(2D)ruddlesden-popper(RP)perovskites with fantastic optoelectronic properties and good stability have attracted tremendous attention for the potential applications in photovolta...Organic-inorganic hybrid two-dimensional(2D)ruddlesden-popper(RP)perovskites with fantastic optoelectronic properties and good stability have attracted tremendous attention for the potential applications in photovoltaics and electroluminescence.Recently,a new allinorganic Cs2PbI2Cl22D perovskite has been proposed with excellent excitonic absorption and improved ambient and thermal stability.Herein,an interesting light-induced phase transition and photochromism in the Cs2PbI2Cl2were reported.Under low fluence light pumping,the room temperature photoluminescence(PL)of Cs2PbI2Cl2is dominated by a weak violet excitonic emission peaked at 412 nm.Surprisingly,the emission color gradually changes from violet to bright red while increasing the laser pumping fluence.This photochromic effect is determined to be caused by forming CsPbI3phase within the Cs2PbI2Cl2crystals,which is efficiently driven by thermal energy.Due to protection by the Cs2PbI2Cl2matrix,the embedded CsPbI3nanocrystals show improved stability than standard pure CsPbI3.Therefore,the Cs2PbI2Cl2perovskite with photochromic feature may find applications in optical encryption,as preliminarily shown in this work.展开更多
基金financial support from Macao Science and Technology Development Fund(FDCT-116/2016/A3,FDCT-091/2017/A2 and FDCT-014/2017/AMJ)the Research Grants(SRG2016-00087-FST,MYRG2018-00148-IAPME)from University of Macao+1 种基金the National Natural Science Foundation of China(91733302,61605073,61935017)the Natural Science Foundation of Guangdong Province,China(2019A1515012186)。
文摘Lead-free double perovskite,Cs2AgBiBr6,with higher stability and lower toxicity than those of its lead counterparts,has been considered a promising alternative for next-generation photovoltaic materials.For practical applications,a facile deposition method that could be used to fabricate high-quality double perovskite films with large grain size is highly desired.However,such kind of facile method has never been established for Cs2AgBiBr6.Herein,high-quality Cs2AgBiBr6thin films with an average grain size of approximately 0.5μm were successfully deposited via a simple onestep spin-coating method by using dimethyl sulfoxide(DMSO)-N,N-dimethylformamide(DMF)mixture with optimized volume ratio as the solvent and chlorobenzene(CB)as the antisolvent.On the basis of satisfactory quality of the film efficient(>1%)Cs2AgBiBr6perovskite solar cells were constructed.Furthermore,the photo-generated charge-carrier transfer from Cs2AgBiBr6to the adjacent carrier extraction layers was systematically investigated via femtosecond transient spectroscopies.This study offers a new pathway to acquiring high-quality Cs2AgBiBr6thin films and provides a useful guide toward the development of high-efficiency double perovskite solar cells in the future.
基金supported by the Macao Science and Technology Development Fund(FDCT-116/2016/A3,FDCT-091/2017/A2,FDCT-014/2017/AMJ and FDCT-199/2017/A3)Start-up Research Grant Fund from University of Macao(SRG2016-00002-FST)+3 种基金Research and Development Grant for Chair Professor Fund from University of Macao(CPG2018-00026-FST)Research Grant(SRG201600087-FST,MYRG2018-00148-IAPME and MYRG2018-00142-IAPME)from University of Macaothe National Natural Science Foundation of China(91733302,61935017 and 61605073)the Natural Science Foundation of Guangdong Province of China(2019A1515012186)。
文摘Organic-inorganic hybrid two-dimensional(2D)ruddlesden-popper(RP)perovskites with fantastic optoelectronic properties and good stability have attracted tremendous attention for the potential applications in photovoltaics and electroluminescence.Recently,a new allinorganic Cs2PbI2Cl22D perovskite has been proposed with excellent excitonic absorption and improved ambient and thermal stability.Herein,an interesting light-induced phase transition and photochromism in the Cs2PbI2Cl2were reported.Under low fluence light pumping,the room temperature photoluminescence(PL)of Cs2PbI2Cl2is dominated by a weak violet excitonic emission peaked at 412 nm.Surprisingly,the emission color gradually changes from violet to bright red while increasing the laser pumping fluence.This photochromic effect is determined to be caused by forming CsPbI3phase within the Cs2PbI2Cl2crystals,which is efficiently driven by thermal energy.Due to protection by the Cs2PbI2Cl2matrix,the embedded CsPbI3nanocrystals show improved stability than standard pure CsPbI3.Therefore,the Cs2PbI2Cl2perovskite with photochromic feature may find applications in optical encryption,as preliminarily shown in this work.
