The exciton-longitudinal-optical-phonon coupling in InGaN/GaN single quantum wells with various cap layer thicknesses  

作　　者：胡晓龙 张江勇 尚景智 刘文杰 张保平 

机构地区：[1]Department of Physics,Laboratory of Micro-Nano Optoelectronics,Xiamen University [2]State Key Laboratory on Integrated Optoelectronics,Institute of Semiconductors,Chinese Academy of Sciences [3]Division of Physics and Applied Physics,School of Physical and Mathematical Sciences,Nanyang Technological University [4]Pen-Tung Sah Micro-Nano Technology Research Center,Xiamen University

出　　处：《Chinese Physics B》2010年第11期653-657,共5页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China (Grant Nos. 60876007 and 10974165);the Research Program of Xiamen Municipal Science and Technology Bureau,China (Grant No. 2006AA03Z110)

摘　　要：This paper studies the exciton-longitudinal-optical-phonon coupling in InGaN/GaN single quantum wells with various cap layer thicknesses by low temperature photoluminescence （PL） measurements. With increasing cap layer thickness, the PL peak energy shifts to lower energy and the coupling strength between the exciton and longitudinal- optical （LO） phonon, described by Huang-Rhys factor, increases remarkably due to an enhancement of the internal electric field. With increasing excitation intensity, the zero-phonon peak shows a blueshift and the Huang-Rhys factor decreases. These results reveal that there is a large built-in electric field in the well layer and the exciton-LO-phonon coupling is strongly affected by the thickness of the cap layer.This paper studies the exciton-longitudinal-optical-phonon coupling in InGaN/GaN single quantum wells with various cap layer thicknesses by low temperature photoluminescence （PL） measurements. With increasing cap layer thickness, the PL peak energy shifts to lower energy and the coupling strength between the exciton and longitudinal- optical （LO） phonon, described by Huang-Rhys factor, increases remarkably due to an enhancement of the internal electric field. With increasing excitation intensity, the zero-phonon peak shows a blueshift and the Huang-Rhys factor decreases. These results reveal that there is a large built-in electric field in the well layer and the exciton-LO-phonon coupling is strongly affected by the thickness of the cap layer.

关 键 词：exciton longitudinal-optical-phonon InGaN/GaN single quantum well GaN cap layer Huang-Rhys factor 

分 类 号：O471.1[理学—半导体物理]