Optical and morphological properties of InGaAs/AlGaAs self-assembled quantum dot nanostructures for 980 nm room temperature emission  

作　　者：G. Trevisi P. Frigeri M. Minelli P. Allegri V. Avanzini S. Franchi 

机构地区：[1]CNR -IMEM Institute,Parco delle Scienze 37a,I-43100 Parma,Italy

出　　处：《Optoelectronics Letters》2007年第3期161-164,共4页光电子快报（英文版）

基　　金：The work has been partially supported by the "SANDiE" Networkof Excellence of EU (contract No. NMP4-CT-2004-500101).

摘　　要：This work deals with the study of optical and morphological properties of InGaAs/AlGaAs quantum dot(QD) structures grown by molecular beam epitaxy(MBE) . Photoluminescence(PL) emission energies,activation energies of PL quenching and QD sizes are studied as functions of the Al content in the AlyGa1-yAs confining layers(CL) . We show that the PL emission energy of In(Ga) As/AlyGa1-yAs QD structures increases with increasing y and that the sizes of InAs/AlyGa1-yAs QDs decrease with increasing y. By the comparison of the experimental results with those of an effective-mass model developed to calculate the QD fundamental transition energies,we show that the blueshift of emission energy has to be ascribed not only to the increase in barrier discontinuities that confine the carriers into QDs but even to effects related to changes of the QD morphology dependent on CL composition. Moreover,we show that the Al content in the barriers determines also the activation energy of thermal quenching of PL,which depends on the thermal escape of carriers from QD levels. These studies resulted in the preparation of structures with efficient light-emission in the 980 nm spectral window of interest for lightwave communications.This work deals with the study of optical and morphological properties of InGaAs/AlGaAs quantum dot （QD） structures grown by molecular beam epitaxy （MBE）. Photoluminescence （PL） emission energies, activation energies of PL quenching and QD sizes are studied as functions of the Al content in the AlyGal-yAs confining layers （CL）. We show that the PL emission energy of In（Ga）As/AlyGal-yAs QD structures increases with increasing y and that the sizes of InAs/AlyGal-yAs QDs decrease with increasing y. By the comparison of the experimental results with those of an effective-mass model developed to calculate the QD fundamental transition energies, we show that the blueshift of emission energy has to be ascribed not only to the increase in barrier discontinuities that confine the carriers into QDs but even to effects related to changes of the QD morphology dependent on CL composition. Moreover, we show that the Al content in the barriers determines also the activation energy of thermal quenching of PL, which depends on the thermal escape of carriers from QD levels. These studies resulted in the preparation of structures with efficient light-emission in the 980 nm spectral window of interest for lightwave communications.

关 键 词：INGAAS AIGAAS 自组装量子点 纳米结构 室温发光 光学性质 形态 

分 类 号：TN304[电子电信—物理电子学]