Effect of growth temperature on photoluminescence of GaNAs/GaAs quantum well structures

The effect of growth temperature on the optical properties of GaAs/GaNxAs1- x quantum wells is studied in detail using photoluminescence (PL) spectrosc opies. An increase in growth temperature up to 580 degrees C is shown to im prove the optical quality of the structures, while still allowing one to ac hieve high (> 3%) N incorporation. This conclusion is based on: (i) an obse rved increase in intensity of the GaNAs-related near-band-edge emission; (i i) a reduction in band-edge potential fluctuations, deduced from the analys is of the PL line shape; and (iii) a decrease in concentration of some exte nded defects detected under resonant excitation of the GaNAs. The thermal q uenching of the GaNAs-related PL emission, however, is almost independent o f the growth temperature and is attributed to a thermal activation of an ef ficient nonradiative recombination channel located in the GaNAs layers. (C) 1999 American Institute of Physics. [S0003-6951(99)03150-2].