量子点超晶格激子系综中的超荧光行为  

Superfluorescence behavior of excitons in a quantum dot superlattice

作　　者：谭继清 王强强 谢微[1] TAN Jiqing;WANG Qiangqiang;XIE Wei(School of Physics and Electronic Science,East China Normal University,Shanghai 200241,China)

机构地区：[1]华东师范大学物理与电子科学学院,上海200241

出　　处：《华东师范大学学报（自然科学版）》2022年第4期163-168,共6页Journal of East China Normal University(Natural Science)

摘　　要：在10 K温度下,利用时间分辨荧光收集系统,研究了钙钛矿量子点超晶格单光子和双光子的荧光发光光谱及激子动力学特征.单光子过程表现出典型的超荧光特征:随着泵浦功率的增加,峰值强度非线性增加,辐射寿命迅速减小.同时,双光子吸收荧光光谱强度呈现二次非线性增加,激子动力学过程与单光子过程呈现出相同特征.这证明,激发密度达到一定强度时,双光子吸收也可以诱导超荧光过程.In this study,photoluminescence spectra are studied in perovskite quantum dot superlattices based on two-photon absorption processes at 10 K.The dynamics of excitons is obtained using a timeresolved photoluminescence detection system.The sample exhibits typical superfluorescence characteristics in the single-photon excitation case:When the pumping power increases,the transient peak intensity increases nonlinearly,and the radiation lifetime decreases rapidly.Meanwhile,the intensities of the twophoton absorption fluorescence spectra are proportional to the square of the excitation power,and the dynamics of excitons under the two-photon absorption case exhibits the same characteristics as those in the single-photon excitation case.Thus,when the excitation density reaches a certain intensity,two-photon absorption can also induce a superfluorescence process.

关 键 词：量子点超晶格 超荧光 双光子吸收 

分 类 号：O472.3[理学—半导体物理]