Anomalous phosphorus cracker temperature-dependent photoluminescence spectra of InGaP grown by solid source molecular beam epitaxy

InGaP grown by solid source molecular beam epitaxy showed lower effective b and-gap energy with increasing phosphorus cracker temperature. Anomalous ph otoluminescence (PL) spectra also indicated that a weaker ordering effect w as initiated when the cracker temperature was higher. Since the variation o f cracker temperature mainly changed the P-2/P-4 ratio, we believe that the more chemically reactive P-2 incorporates more In into the epilayer. There fore, InGaP grown under a more Pt-rich condition has a higher In content wh ich results in the lower band-gap energy instead of having an ordering effe ct.