Influence of applied electric field on the absorption coefficient and subband distances in asymmetrical AlN/GaN coupled double quantum wells  

作　　者：岑龙斌 沈波 秦志新 张国义 

机构地区：[1]State Key Laboratory of Artificial Microstructure and Mesoscopic Physics,School of Physics,Peking University

出　　处：《Chinese Physics B》2009年第9期3905-3908,共4页中国物理B（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant Nos 60806042,10774001,60736033,60890193 and 60628402);National Basic Research Program of China (Grant Nos 2006CB604908 and 2006CB921607);the Research Fund for the Doctoral Program of Higher Education in China (Grant Nos 200800011021 and 20060001018);Beijing Natural Science Foundation (Grant No 4062017)

摘　　要：The influence of applied electric fields on the absorption coefficient and subband distances in asymmetrical A1N/GaN coupled double quantum wells （CDQWs） has been investigated by solving SchrSdinger and Poisson equations self-consistently. It is found that the absorption coefficient of the intersubband transition （ISBT） between the ground state and the third excited state （lodd - 2even） can be equal to zero when the electric fields are applied in asymmetrical A1N/GaN CDQWs, which is related to applied electric fields induced symmetry recovery of these states. Meanwhile, the energy distances between 1odd - 2even and 1even - 2even subbands have different relationships from each other with the increase of applied electric fields due to the different polarization-induced potential drops between the left and the right wells. The results indicate that an electrical-optical modulator operated within the opto-communication wavelength range can be realized in spite of the strong polarization-induced electric fields in asymmetrical A1N/GaN CDQWs.The influence of applied electric fields on the absorption coefficient and subband distances in asymmetrical A1N/GaN coupled double quantum wells （CDQWs） has been investigated by solving SchrSdinger and Poisson equations self-consistently. It is found that the absorption coefficient of the intersubband transition （ISBT） between the ground state and the third excited state （lodd - 2even） can be equal to zero when the electric fields are applied in asymmetrical A1N/GaN CDQWs, which is related to applied electric fields induced symmetry recovery of these states. Meanwhile, the energy distances between 1odd - 2even and 1even - 2even subbands have different relationships from each other with the increase of applied electric fields due to the different polarization-induced potential drops between the left and the right wells. The results indicate that an electrical-optical modulator operated within the opto-communication wavelength range can be realized in spite of the strong polarization-induced electric fields in asymmetrical A1N/GaN CDQWs.

关 键 词：A1N/GaN CDQWs electrical-optical modulator intersubband transition 

分 类 号：O471.1[理学—半导体物理]