V形GaAs/AlGaAs量子线结构的微区光致发光谱研究

THE MICRO-PHOTOLUMINESCENCE OF A SINGLE V-GROOVE GaAs/AlGaAs QUANTUM WIRE

在室温下用显微光致发光的方法对单根V形GaAs/AlGaAs量子线进行了沿垂直于量子线方向的空间分辨扫描测试 ,观察到各种量子结构的光致发光谱随空间位置的变化 .在量子线区域附近观察到来自量子线 (QWR)、颈部量子阱 (NQWL)和垂直量子阱 (VQWL)等各种结构的发光 ,而在距离量子线约 1μm以远的发光光谱表现出侧面量子阱 (SQWL)的发光 .对全部发光光谱用高斯线形进行了拟合 ,发现QWR和SQWL的发光包含了两个荧光峰 ,将它们分别归诸为电子到轻、重空穴的跃迁 .拟合后发光强度的空间变化直接确定了与量子线结构相关的发光起源 ,并且反映出由于载流子由SQWL迁移进入QWR造成SQWL发光峰的淬灭 .

The micro\|photoluminescence(μ\|PL) scan has been performed on a single V\|groove GaAs/AlGaAs quantum wire in the direction perpendicular to the wire.The variation of μ\|PL spectra from various quantum structures with different spatial positions has been observed.In the region of quantum wire (QWR) the PL spectra contain the peaks from QWR,necking quantum well (NQWL) and vertical quantum well (VQWL),while in the area about 1?μm and farther away from the QWR the PL spectra show the peaks from side\|wall quantum well (SQWL) and top quantum well (TQWL).All the scanned PL spectra have been fitted by Gauss line shape.The asymmetric PL peaks of QWR and SQWL were decomposed into two components which were ascribed to the optical transitions between the electron ground state in the conduction band and the heavy hole and the light hole ground states in the valence band.The variation of PL intensity from luminescent components with the spatial positions directly demonstrates the origin of the photoluminescence relating to different quantum structures,and reflects the carrier transfer from SQWL to QWR,resulting in the PL quenching of SQWL.