Laboratoire des Matériaux Semiconducteurs, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
ACS Nano. 2010 Oct 26;4(10):5985-93. doi: 10.1021/nn101604k.
InAs quantum dot arrays are obtained on GaAs nanowire facets by molecular beam epitaxy. The GaAs nanowires are first grown by the gallium-assisted catalyst-free method. Decoration of the nanowire facets with InAs quantum dots is achieved only when the facets are capped with an ultrathin AlAs layer, as demonstrated by atomic force, high-resolution electron microscopy, and energy-dispersive X-ray spectroscopy line scans. The excitation of single and double excitons in the quantum dots are demonstrated by low-temperature photoluminescence spectroscopy realized on the single nanowires. This new type of heterostructures opens a new avenue to the fabrication of highly efficient single-photon sources, novel quantum optics experiments, as well as the realization of intermediate-band nanowire solar cells for third-generation photovoltaics.
通过分子束外延，在 GaAs 纳米线的（110）晶面上得到了 InAs 量子点阵列。GaAs 纳米线首先通过无催化剂的 Ga 辅助方法生长。只有当纳米线的（110）晶面被一层超薄的 AlAs 覆盖时，才能在晶面上实现 InAs 量子点的装饰，原子力显微镜、高分辨率电子显微镜和能量色散 X 射线能谱线扫描证明了这一点。低温光致发光光谱实验证明了量子点中单激子和双激子的激发。这种新型异质结构为制造高效单光子源、新型量子光学实验以及实现第三代光伏的中能带纳米线太阳能电池开辟了新途径。
