Effects of confined longitudinal and interface optical phonons on excitons in an asymmetric quantum well  

作　　者：DENG YanPing TIAN Qiang 

机构地区：[1]Department of Physics, Beijing Normal University, Beijing 100875, China

出　　处：《Science China(Physics,Mechanics & Astronomy)》2011年第9期1593-1599,共7页中国科学：物理学、力学、天文学（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant No. 10574011)

摘　　要：The interaction between exciton and confined longitudinal optical （LO） phonons, interface optical （IO） phonons in an asymmetric Ga1-xAlxAsIGaAslGao.TAlo.3As square quantum well is investigated. By applying the LLP-like transformation and variational approach, the numerical results are obtained as functions of the well width and asymmetric-degree of well. The exciton-optical phonons interaction-energy has a minimum value with the increase of the well width. It is demonstrated that the LO-phonon energy-contribution increases while the IO-phonon contribution decreases as the well width increases gradually. The energy-contribution of LO-phonon in symmetric and asymmetric square quantum well does not have too much difference, but the IO-phonon contribution varies apparently. The exciton binding-energy monotonically decreases with the increase of the well width and is proportional to the left-barrier height.The interaction between exciton and confined longitudinal optical (LO) phonons, interface optical (IO) phonons in an asymmetric Ga 1 x Al x As/GaAs/Ga 0.7 Al 0.3 As square quantum well is investigated. By applying the LLP-like transformation and variational approach, the numerical results are obtained as functions of the well width and asymmetric-degree of well. The exciton-optical phonons interaction-energy has a minimum value with the increase of the well width. It is demonstrated that the LO-phonon energy-contribution increases while the IO-phonon contribution decreases as the well width increases gradually The energy-contribution of LO-phonon in symmetric and asymmetric square quantum well does not have too much difference but the IO-phonon contribution varies apparently. The exciton binding-energy monotonically decreases with the increase of the well width and is proportional to the left-barrier height.

关 键 词：asymmetric square quantum well EXCITON PHONONS 

分 类 号：O471[理学—半导体物理] TN914.3[理学—物理]