摘要
Hybrid perovskite nanocrystals(NCs)are widely used in various applications,due to their desirable optoelectronic characteristics.However,the related applications are usually hindered by their poor long-term stability.In this work,we have synthesized one kind of CH_(3)NH_(3)PbBr_(3)(MAPbBr_(3))NC that is heteroepitaxially grown with an MA_(1-x)Cs_(x)PbBr_(3) shell,with the aim to optimize the optical properties of the former.It is found that the MAPbBr_(3)/MA_(1-x)Cs_(x)PbBr_(3) core/shell NCs possess optimized optical stability.Through the measurement of the temperature-dependent photoluminescence spectrum,it is confirmed that the core/shell NCs exhibit weaker electron-phonon coupling strength and larger exciton binding energy than the bare MAPbBr_(3) NCs.Interestingly,the core/shell NCs display significantly prolonged biexciton Auger lifetime and enlarged two-photon absorption.Impressively,two-photon pumped amplified stimulated emission is only observed in the core/shell NCs but not in the bare NCs,enabling the former to be promising for application in nonlinear optoelectronic devices.
基金
the National Natural Science Foundation of China(62174079)
the Guangdong Basic and Applied Basic Research Foundation(2019A1515012094 and 2022A1515011246)
the Project of Department of Education of Guangdong Province(2018KTSCX198)
the Science and Technology Planning Project of Shenzhen Municipality(JCYJ20190808121211510 and JCYJ20190808142603561).
