Narrow band gap GaInNAsSb material grown by metal organic vapor phase epitaxy (MOVPE) for solar cell applications

Bulk, lattice-matched GaInNAsSb material has been grown by metal organic vapor phase epitaxy (MOVPE) for applications in concentrated multi-junction solar cells. The present paper outlines the growth conditions for lattice-matched GaInNAsSb with band gap energies close to 1.0 eV. Metal organic antimony (Sb) precursors, triethyl antimony (TESb) and trimethyl antimony (TMSb), were utilized and incorporation studies were carried out over the growth temperature range of 515–550 °C. High-resolution X-ray diffraction (HRXRD) and photoluminescence (PL) emission spectra were used to optimize the growth conditions and compare the material properties between samples of differing nitrogen (N) content. The impact of a two-stage, post-growth annealing sequence on peak PL intensity was studied with respect to temperature, time (stabilized) and carrier gas overpressure (unstabilized). Optimization of the post-growth annealing conditions of this material system was found to improve the peak PL emission intensity by 7× compared to as-grown material.