MINORITY ELECTRON LIFETIMES IN HEAVILY DOPED P-TYPE GAAS GROWN BY MOLECULAR-BEAM EPITAXY

Minority electron lifetimes in molecular beam epitaxy grown Be-doped p-type GaAs are characterized systematically. Samples grown at temperatures from 550 to 700-degrees-C have hole concentrations from 10(17) to 10(20) cm-3. Although electron lifetime in samples grown at temperatures higher than 650-degrees-C remains nearly constant for each free-carrier concentration, it decreases significantly at lower growth temperatures. These tendencies are observed in common for various hole concentrations. These results can be explained in terms of an increase in nonradiative recombination centers incorporated during growth.