MBE growth of highly strained InGaPN/GaPN quantum well with high indium content

Abstract

Highly strained In x Ga 1 −x P 1 −y N y /GaP 1 −z N z quantum wells (QWs) with direct transition ( x>27%) were grown on GaP (1 0 0) substrates by solid-source molecular beam epitaxy (SS-MBE). The interfaces of In 0.33Ga 0.67P 0.984N 0.016/GaP 0.988N 0.012 QW were smooth and straight. However, the interfaces of In 0.45Ga 0.55P 0.98N 0.02/GaP 0.984N 0.016 QW were roughened showing well-width fluctuations. From our experimental and calculated results, the conduction band offsets were very small for both the InGaPN/GaPN QWs grown on GaP substrates. The photoluminescence (PL) of the InGaPN/GaPN QWs could be based on the recombination between electrons in the conduction band and holes at the first quantum level in the valence band. Rapid thermal annealing at 800 °C for 30 s in a N 2 ambient improved the integrated PL intensity by a factor of 3 with a red-shift. This improvement in optical properties could be attributed to annihilation of N-related defects through atomic rearrangement. The highly strained In 0.33Ga 0.67P 0.984N 0.016/GaP 0.988N 0.012 QW was maintained after thermal annealing below 800 °C for 30 s, although the local atomic rearrangement could occur.