Excitation-power-density-dependent micro-photoluminescence from selective-area-grown hexagonal nanopillars with single InGaAs/GaAs quantum well on the GaAs (111)B substrate

We report on the fabrication of the highly uniform hexagonal nanopillars with single InGaAs/GaAs quantum well (QW) on the GaAs (111)B substrate by selective-area metal organic vapor phase epitaxy. The standard size deviation of the fabricated nanopillars with single InGaAs/GaAs QW is about 2% and the standard deviation in their height about 5%. The excitation-power-density-dependent micro-photoluminescence (mu-PL) from the selective-area-grown hexagonal nanopillars with single InGaAs/GaAs QW on the GaAs (111)B substrate was measured at 4.2 k, 50 k, 100 k and 150 k. With an increase in the excitation power density, the PL peak position shifts to the higher energy. A model considering the piezoelectric effect, the photon-screening effect and the band-filling effect was used to calculate the PL peak positions. The agreement between the experimental results and the calculation results is good. We also find that the diffusion length of the carriers in the nanopillars with single InGaAs/GaAs QW reduces greatly compared to the general value in semiconductors, which is mainly due to the existence of rotation twins. With an increase in the excitation power density, the PL intensity increases and the PL peak width increases, which also can be explained qualitatively with the above model.