Optical Characterization of In(Ga)As/GaAs Self-assembled Quantum Dots Using Near-Field Spectroscopy

Abstract

Reduced dimensions of carrier motion down to zero-dimensional (OD) can be realized in semiconductor quantum dots. In such OD systems, fully quantized states will significantly improve performance in photonic and electronic device applications [1]. One of the most representative structures is self-assembled quantum dots (SAQDs), using the Stranski-Krastanow (SK) growth mode, in which dots form spontaneously during the overgrowth of highly mismatched materials, as shown in Fig. 1. Because of the absence of processing by lithography and etching, SAQDs provide defect-free structures with high emission efficiency. In addition, their high dot density (> 1011 dots/cm2) and ability to stack vertically enhance carrier density, which is important for realizing quantum dot lasers with low threshold current. Indeed, injection lasers with low threshold current have already been demonstrated using InGaAs/GaAs SAQDs [2].KeywordsDetection EnergyRelaxation EnergyHigh Excited StateLongitudinal Optical PhononLongitudinal OpticalThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.