垂直堆垛InAs量子点材料的分子束外延生长

Growth of Vertically Stacked and Self-Assembled InAs Quantum Dots

用MBE设备以Stranski Krastanov生长方式外延生长了 5个周期垂直堆垛的InAs量子点 ,在生长过程中使用对形状尺寸控制法来提高垂直堆垛InAs量子点质量和均匀性。样品外延的主要结构是 5 0 0nm的GaAs外延层 ,15nm的Al0 .5Ga0 .5As势垒外延层 ,5个周期堆跺的InAs量子点 ,5 0nm的Al0 .5Ga0 .5Asnm势垒外延层等。在生长过程中用反射式高能电子衍射仪 (RHEED)实时监控。生长后用原子力显微镜 (AFM)进行表面形貌的表征 ,再利用光制发光 (PL)

The epilayer of vertically stacked, self assembled InAs Quantum Dots (QDs) was grown by molecular beam epitaxy (MBE) in Stranski Krastanov growth mode with solid sources in non cracking K cells. The surface morphologies were measured by reflection high energy electron diffraction (RHEED) and atomic force microscopy (AFM). To improve the morphology, a size and density controlled growth procedure for the vertically stacked InAs QDs was employed. The 5 period vertically stacked InAs QDs in the barrier layer of a field effect type structure were measured by photoluminescence property.