Single photon emission and recombination dynamics in self-assembled GaN/AlN quantum dots  

作　　者：Johann Stachurski Sebastian Tamariz Gordon Callsen Raphaël Butté Nicolas Grandjean 

机构地区：[1]Institute of Physics,École Polytechnique Fédérale de Lausanne,EPFL,CH-1015 Lausanne,Switzerland [2]Present address:UniversitéCôte d’Azur,CNRS,CRHEA,F-06560 Valbonne,France [3]Present address:Institut für Festkörperphysik,Universität Bremen,28359 Bremen,Germany

出　　处：《Light(Science & Applications)》2022年第5期751-765,共15页光（科学与应用)（英文版）

基　　金：supported by the Swiss National Science Foundation through Grants 200021E_15468 and 200020_162657;by the Marie SklodowskaCurie action“PhotoHeatEffect”(Grant no.749565)within;European Union’s Horizon 2020 research and innovation program.

摘　　要：Ⅲ-nitride quantum dots(QDs)are a promising system actively studied for their ability to maintain single photon emission up to room temperature.Here,we report on the evolution of the emission properties of self-assembled GaN/AlN QDs for temperatures ranging from 5 to 300 K.We carefully track the photoluminescence of a single QD and measure an optimum single photon purity of g^((2))(0)=0.05±0.02 at 5 K and 0.17±0.08 at 300 K.We complement this study with temperature dependent time-resolved photoluminescence measurements(TRPL)performed on a QD ensemble to further investigate the exciton recombination dynamics of such polar zero-dimensional nanostructures.By comparing our results to past reports,we emphasize the complexity of recombination processes in this system.Instead of the more conventional mono-exponential decay typical of exciton recombination,TRPL transients display a bi-exponential feature with short-and long-lived components that persist in the low excitation regime.From the temperature insensitivity of the long-lived excitonic component,we first discard the interplay of dark-to-bright state refilling in the exciton recombination process.Besides,this temperature-invariance also highlights the absence of nonradiative exciton recombinations,a likely direct consequence of the strong carrier confinement observed in GaN/AlN QDs up to 300 K.Overall,our results support the viability of these dots as a potential single-photon source for quantum applications at room temperature.

关 键 词：temperature. process. QUANTUM 

分 类 号：O4[理学—物理]