Growth of GaNxAsyP1-x-y alloys on GaP(100) by gas-source molecular beam epitaxy

The authors report epitaxial growth of dilute nitride GaNxAsyP1-x-y on GaP(100) via a linearly graded GaAsxP1-x metamorphic buffer. The As content is in situ determined by group-V-induced reflection high energy electron diffraction intensity oscillation, while the N content is determined by x-ray diffraction. Room-temperature photoluminescence (PL) is observed for the top GaNxAsyP1-x-y layer and in temperature dependent PL, the peak position shows S-shape curve, indicative of defect states in the bandgap. Room-temperature PL intensity is drastically increased after rapid thermal annealing (RTA) and the results suggest GaNxAsyP1-x-y with different N content requires different optimal RTA temperature for optical performance. (C) 2012 American Vacuum Society. [DOI:10.1116/1.3680603]