Improvement in the internal quantum efficiency of InN grown over nanoporous GaN by the reduction of Shockley-Read-Hall recombination centers

Abstract

InN was grown over nanoporous GaN by metal-organic chemical vapor deposition. Additional free surfaces in the numerous GaN nanopores reduced the surface energy and encouraged extensive nucleation and uniform growth of InN nanoislands. Conversely, coarse and poorly distributed InN islands grew on planar GaN surfaces. Non-radiative Shockley-Read-Hall recombination rates were significantly lower in InN grown on nanoporous GaN than those on planar GaN, leading to the internal quantum efficiency increasing from 3% to 20%. This is attributed to the reorientation of InN during growth over the underlying nanoporous GaN, which relieved misfit stress and reduced defects associated with Shockley-Read-Hall recombination. © 2013 AIP Publishing LLC.