Effect of bismuth surfactant on the structural, morphological and optical properties of self-assembled InGaAs quantum dots grown by Molecular Beam Epitaxy on GaAs (001) substrates

•The structural, morphological and optical properties of self-assembled In0.5Ga0.5As QDs grown by Moleculra Beam Epitaxy on GaAs substrates at various growth temperatures with and without exposure to bismuth (Bi) flux have been investigated.•Atomic force microscopy, scanning electron microscopy, transmission electron microscopy and photoluminescence (PL) measurements were analysed.•The PL intensity from QDs was enhanced by 1.2 times by introducing Bi as a surfactant as compared to InGaAs/GaAs control sample grown without Bi.•A red-shift of the PL peak energy of about 40 meV was also observed when the InGaAs QDs were grown by using Bi evidencing that Bi surfactant affects considerably the size of QDs.•The QDs grown with Bi surfactant exhibited a higher degree of size uniformity as demonstrated by the observation of narrower FWHM (Full-Width at half Maximum) of the PL peaks•The growth temperature of 495 °C was found to be optimal in terms of optical efficiency.