InGaAs/GaAs应变脊形量子线分子束外延非平面生长研究

提出了新型InGaAs/GaAs应变脊形量子线结构．这种应变脊形量子线结合了非平面应变外延层中沿不同晶向能带带隙的变化、非平面生长应变层In组分的变化，以及非平面外延层厚度的变化等三方面共同形成的横向量子限制效应的综合作用．在非平面GaAs衬底上用分子束外延生长了侧面取向为（113）的脊形AlAs/In GaAs/AlAs应变量子线．用10K光致荧光谱测试了其发光性质．用Kronig-Penney模型近似计算了这种应变脊形结构所具有的横向量子限制效应，发现其光致荧光谱峰位的测试结果，与计算结果相比，有10meV的“蓝移”．认为这一跃迁能量的“蓝移”是上述三方面横向量子限制效应综合作用的结果 关键词：

InGaAs/GaAs STRAINED RIDGE QUANTUM WIRES GROWN-BY MBE ON NONPLANAR SUBSTRATE

The structures of the strained InGaAs/GaAs ridge quantum wires(QWRs) were proposed and the samples fabricated by MBE growth on patterned substrate. High resolution scanning electron microscope (SEM) studies showed that these ridge structures were formed with (001) top and (113) side faces.The photoluminescence(PL) measurements indicated that the lateral quantum confinement effects of the ridge-QWRs caused the quantum confined energy a 10meV blue-shift, which agreed with the approximate calculations for the strained ridge-QWR structure using Kronig-Penney model. This strainedridge-QWRs consisted of three aspects of lateral confinement effects.Firstly the thickness of ridge quantum wells on the ridge top was larger than that on the side surfaces;Secondly the indium concentrations on the ridge-top region was higher than that on the side region;Thirdly the strain effects led to a larger energy gaps in side (113) plane than that in the (001) ridge top.The above three factors were cooperated to enhance the confinement effects on the lateral motion of carriers in strained ridge QWRs.