Photoluminescence studies of GaSbBi quantum dots grown on GaAs by liquid phase epitaxy

Abstract

Liquid phase epitaxial growth from a saturated GaSb solution in Ga with 1.3 at.% Bi, on GaAs substrates is shown to produce quantum dots with a Bi content of 0.5 at.%. The height and dimensions of the QDs are investigated by field effect scanning electron microscopy and atomic force microscopy. The density of the small QDs is approximately 4.3 × 109cm−2, with dimensions in the range of 20–100 nm and height of ∼10 nm. Theoretical calculations reveal that the QDs have band alignment structure of type-II as predicted from GaSbBi bulk band structure. The 12 K photoluminescence (PL) of the QDs shows broad emission band in the range 1.25–1.37 eV. Gaussian deconvolution is used to resolve the broad peak into three individual PL emission peaks which are thoroughly explored by their dependence on temperature and excitation power.