Improved minority carrier lifetime in p-type GaN by suppressing the non-radiative recombination process

Abstract

Time-resolved photoluminescence and capacitance-voltage measurement were performed on p-type GaN and InGaN films to study the minority carrier recombination mechanism. The minority carrier lifetime (τ PL) for p-GaN with a Mg concentration of 1.7 × 1019 cm−3 was 46 ps. The non-radiative recombination due to gallium vacancies (V Ga)-related defects is confirmed to dominate the minority carrier transport process. To suppress the formation of V Ga defects, the indium atoms were added into p-GaN. As a consequence, the V Ga-related non-radiative recombination centers were reduced from 8 × 1015 to 5 × 1014 cm−3 and a record long τ PL of 793 ps was obtained for p-In0.035Ga0.95N film.