After nanocrystals synthesis,the purification process with anti-solvents is an essential step to get clean nanocrystals,which could get rid of the by-products of the synthesis.It is generally recognized that this proc...After nanocrystals synthesis,the purification process with anti-solvents is an essential step to get clean nanocrystals,which could get rid of the by-products of the synthesis.It is generally recognized that this process could bring a positive effect for the afterward optoelectronic applications.Unfortunately,we found that the optical properties and photostability of perovskite CsPbBr3 nanocrystals were unavoidably deteriorated after they were washed with anti-solvents,and this deterioration is strongly related to the decreasing of surface ligands density.Therefore,in this paper,we tried to purposely not wash the CsPbBr3 nanocrystals solution after adding didodecyl dimethylammonium bromide (DDAB),and found the existing of DDAB in solution could result in a dramatically enhanced photostability.Inspired by these results,we proposed a new strategy to stabilize perovskite nanocrystals from the view of packaging process:adding protective ligands into the perovskite nanocrystals resin directly,then encapsulating them on blue light-emitting diodes (LED) chips.Surprisingly,stable LED devices (20 mA,2.7V) were achieved by this way,which can keep 80% of the initial photoluminescence (PL) intensity for more than 50 h,while the devices with CsPbBr3 nanocrystals without adding protective ligands into resin dropped to 50% of their initial PL intensity within 6 h.This approach offers a new thought to stabilize perovskite nanocrystals as down-conversion phosphor in quantum dots liquid crystal display.展开更多
基金supported by the National Natural Science Foundation of China(No.11274205,No.11274206,and No.11504206)Natural Science Foundation of Shandong Province(ZR2022MA016,ZR2020ME231)Key Research and Development Project of Shan-dong province(No.2019GGX102050).
基金the Major National Science and Technology Special Project of Water Pollution Control and Remediation (No.2017ZX07202)the National Natural Science Foundation of China (No.21773155)Shanghai Sailing Program (No.19YF1422200).
文摘After nanocrystals synthesis,the purification process with anti-solvents is an essential step to get clean nanocrystals,which could get rid of the by-products of the synthesis.It is generally recognized that this process could bring a positive effect for the afterward optoelectronic applications.Unfortunately,we found that the optical properties and photostability of perovskite CsPbBr3 nanocrystals were unavoidably deteriorated after they were washed with anti-solvents,and this deterioration is strongly related to the decreasing of surface ligands density.Therefore,in this paper,we tried to purposely not wash the CsPbBr3 nanocrystals solution after adding didodecyl dimethylammonium bromide (DDAB),and found the existing of DDAB in solution could result in a dramatically enhanced photostability.Inspired by these results,we proposed a new strategy to stabilize perovskite nanocrystals from the view of packaging process:adding protective ligands into the perovskite nanocrystals resin directly,then encapsulating them on blue light-emitting diodes (LED) chips.Surprisingly,stable LED devices (20 mA,2.7V) were achieved by this way,which can keep 80% of the initial photoluminescence (PL) intensity for more than 50 h,while the devices with CsPbBr3 nanocrystals without adding protective ligands into resin dropped to 50% of their initial PL intensity within 6 h.This approach offers a new thought to stabilize perovskite nanocrystals as down-conversion phosphor in quantum dots liquid crystal display.
