Fabrication and excitation-power-density-dependent micro-photoluminescence of hexagonalnanopillars with a single InGaAs/GaAs quantum well

Abstract

Hexagonal nanopillars with a single InGaAs/GaAs quantum well (QW) were fabricated on aGaAs (111)B substrate by selective-area metal–organic vapor phase epitaxy. The standarddeviations in diameter and height of the nanopillars are about 2% and 5%, respectively.Zincblende structure and rotation twins were identified in both the GaAs and the InGaAs layersby electron diffraction. The excitation-power-density-dependent micro-photoluminescence(μ-PL) of the nanopillars was measured at 4.2, 50, 100 and 150 K.It was shown that, with increasing excitation power density, theμ-PL peak’s positions shift to a higher energy, and their intensity and width increase,which were rationalized using a model that includes the effects of piezoelectricity,photon-screening and band-filling. It was also revealed that the rotation twins significantlyreduce the diffusion length of the carriers in the nanopillars, compared to that in theregular semiconductors.