The non-radiative loss in a perovskite,mainly resulting from thermal defects and halogen vacancies,has always been an important factor affecting its luminescence properties.The addition of a lithium ion has been demon...The non-radiative loss in a perovskite,mainly resulting from thermal defects and halogen vacancies,has always been an important factor affecting its luminescence properties.The addition of a lithium ion has been demonstrated to be an effective way to reduce the nonradiative recombination in perovskitefilms,mainly acting on the surface/interface of thefilms.However,few studies have focused on its role in col loidal quantum dots.Herein,we have used LiBr as a new dual-defect passivation agent in colloidal CsPbX_(3)(X=Br andⅠ)quantum dots to reduce the capture ability of the defects for excited electrons,leading to an effective reduction of the non-radiative recombination.The mechanism of LiBr doping in CsPbX_(3)(X=Br andⅠ)quantum dots was studied by exploring its photodynamic process at room temperature and low temperature.Our results show that an appropriate concentration of LiBr can not only passivate the halide vacancy and thermal defect to reduce the nonradiative recombination,but also improve the phase stabi lity caused by halide migration.展开更多
基金supported by the National Natural Science Foundation of China-Yunnan Joint Fund(U1902222)the National Natural Science Foundation of China(11774138,11664022,51862020 and 11804255)+1 种基金the Foundation of Yunnan Province(2019HC016)the project for personal training fund supported by Kunming University of Science and Technology(KKSY201632046).
文摘The non-radiative loss in a perovskite,mainly resulting from thermal defects and halogen vacancies,has always been an important factor affecting its luminescence properties.The addition of a lithium ion has been demonstrated to be an effective way to reduce the nonradiative recombination in perovskitefilms,mainly acting on the surface/interface of thefilms.However,few studies have focused on its role in col loidal quantum dots.Herein,we have used LiBr as a new dual-defect passivation agent in colloidal CsPbX_(3)(X=Br andⅠ)quantum dots to reduce the capture ability of the defects for excited electrons,leading to an effective reduction of the non-radiative recombination.The mechanism of LiBr doping in CsPbX_(3)(X=Br andⅠ)quantum dots was studied by exploring its photodynamic process at room temperature and low temperature.Our results show that an appropriate concentration of LiBr can not only passivate the halide vacancy and thermal defect to reduce the nonradiative recombination,but also improve the phase stabi lity caused by halide migration.
