Improving properties of GaInNAs with a short-period GaInAs/GaNAs superlattice

Short-period superlattices (SLs) of GaInAs/GaNAs were grown by gas-source m olecular beam epitaxy. Hall measurement shows electron mobility is improved by a factor of almost two. Improvement of electron mobility can be attribu ted to the smaller effective mass of the SL structure. The photoluminescenc e (PL) intensity is improved by rapid thermal annealing (RTA). The PL inten sity of digital alloys is 2.5-3 times higher than that of the random alloy at room temperature, and the improvement is even greater at low temperature (10 K) by a factor of about 12, The optimized RTA condition for short-peri od SLs is 700<^>C and 10s in Nz ambient. Photoconductive decay measurements show longer carrier lift time for the: SL samples, 0.2 mus vs. 0.1 mus for the random alloy, which could be caused by charge separation due to the ty pe-II band lineup of the GaIn0.08As/GaN0.03As SLs. (C) 2001 Elsevier Scienc e B,V. All rights reserved.