ORDERING IN STRAINED GAXIN1-XP QUANTUM-WELLS GROWN BY METALORGANIC VAPOR-PHASE EPITAXY

Strained GaInP quantum wells with AlGaInP barriers have been grown by metalorganic vapor phase epitaxy (MOVPE). The influence of strain in s ingle quantum wells on the optical properties is examined by photolumi nescence. The emission energy of strongly compressively strained quant um wells shows an anomalous temperature dependence and a shift of 13 m eV per decade of excitation power. This is interpreted as an accurate measure of the critical strain where strain relaxation occurs. By vary ing growth temperature and substrate orientation, the influence of ord ering in strained and unstrained quantum wells is examined. Whereas un strained quantum wells show a similar band gap reduction as bulk GaInP , this is significantly weakened in strained quantum wells. This has t wo reasons. For one, the degree of ordering is limited due to unequal Ga and In amounts. Additionally, according to Wei et al. [Appl. Phys. Lett. 64 (1994) 757], a further reduction is expected if the joint inf luence of strain and ordering is taken into account.