Influence of Pb vs Ga solvents during liquid phase epitaxy on the optical and electrical properties of GaSbBi layers

We have investigated the influence of Pb vs Ga solvents during the liquid phase epitaxial growth of GaSbBi layers on the overall physical, optical, and electrical properties of the material. 10 K photoluminescence (PL) measurements show narrower PL linewidths in layers grown from the Pb solvent compared to that obtained for layers grown under similar conditions using Ga as the solvent. This is an indication of the improved crystalline quality of the material grown from the Pb solvent. GaSbBi layers grown from Pb solvents show a reduction of the carrier concentration by over one order of magnitude than that measured in the corresponding materials grown from Ga solvents. Detailed analysis of the core level transitions, revealed by X-ray photoelectron spectroscopy, indicates the generation of a lesser number of VGa and antisite GaSb defects responsible for the residual hole concentration in GaSb and GaSbBi layers grown from Pb solvents than in the same materials grown using Ga as the solvent. This is suggested as the main reason for the observed reduction of carrier concentration in the layers grown from the Pb solvent.