半导体量子点中的双激子发光  

Biexciton Emission in Semiconductor Quantum Dots

作　　者：黄鹏 张用友 钟海政[1] Huang Peng;Zhang Yongyou;Zhong Haizheng(MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices,School of Materials Science&Engineering,Beijing Institute of Technology,Beijing 100081,China;Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems,School of Physics,Beijing Institute of Technology,Beijing 100081,China)

机构地区：[1]北京理工大学材料学院低维量子结构与器件工信部重点实验室,北京100081 [2]北京理工大学物理学院纳米光子学与超精密光电系统北京市重点实验室,北京100081

出　　处：《中国激光》2023年第1期17-28,共12页Chinese Journal of Lasers

基　　金：北京市自然科学基金(Z210018)。

摘　　要：双激子发光是半导体材料在高激发强度下形成两个激子后复合发光的一种物理过程。相较于块体材料,量子点体积小、载流子受限、能级分立,从而具有独特的双激子发光特性,具体表现为双激子结合能大,级联发射中的光子对是极化反对称的,激子对的俄歇复合效应强。从双激子发光研究的发展历程出发,重点介绍了量子点双激子发光的基本原理、光谱特性,特别是量子效应对量子纠缠和光增益的影响。讨论了量子点双激子发光在纠缠光源、量子点激光器等方面的应用潜力和目前所面临的挑战。Significance Biexcitons are exciton pairs which interact via Coulomb interactions and recombine to emit two photons. Compared with single excitons, biexcitons are achieved under a high excitation intensity. The physical model of the biexciton can be simplified as two electrons at the bottom of the conduction band and two holes at the top of the valence band. The luminescence process of biexcitons involves the cascade recombination of two excitons, and the intensity of the biexcitons shows a quadratic scale as a function of the excitation intensity.Biexcitons were first observed in CuCl by Mysyrowicz et al. in 1968 and then extended to other semiconductor materials, including Ⅱ-Ⅵ(ZnSe and CdS) and Ⅲ-Ⅴ(GaAs). In the 1980s, the study of biexcitons spread to low-dimensional semiconductors, such as quantum wells or quantum dots(QDs), resulting in the discovery of entangled photon pairs as well as predicted advances as a laser gain medium. In the last 40 years, QDs have been widely studied owing to their size-dependent optical properties and potential applications in photonics and optoelectronics. Owing to their well-known quantum confinement effects, QDs offer strong light absorption and a discrete electronic state structure. Therefore, biexcitons in QDs have unique features, including the large binding energy, correlated polarization of the emitted photons, low threshold,and enhanced temperature stability in lasing. These properties provide the advantages of realizing an on-demand entangled photon source and laser diodes.Progress The entangled photons can be generated by biexciton-exciton cascade emission or Hong-Ou-Mandel(HOM) interference from indistinguishable photons in QDs(Fig. 5). The degenerate exciton state is a superposition state and emits an exciton photon with opposite circular polarization with respect to the polarization of previously emitted biexciton photons. In 2006, Stevenson et al.demonstrated entangled photon pairs from a single InAs QD. Subsequently, InAs QDs were optimized to achieve hig

关 键 词：量子光学 量子点 双激子 纠缠光子源 俄歇复合 光增益 

分 类 号：TN244[电子电信—物理电子学]