MINORITY-CARRIER PROPERTIES OF GAAS ON SI GROWN BY METALORGANIC CHEMICAL-VAPOR-DEPOSITION

Minority carrier properties of 3-mum-thick n-type GaAs on Si with a strained layer superlattice and thermal cycle annealing grown by metalorganic chemical vapor deposition (MOCVD) have been characterized by cathodeluminescence (CL) and time-resolved photoluminescence (TRP). The calculated TRP decay curve is investigated by changing the material parameters (bulk lifetime and surface recombination velocity). The minority carrier lifetime of GaAs on Si has been determined by fitting the experimentally obtained TRP curve to the calculated one. The minority carrier lifetime increases and the dark-spot defect density decreases with increasing number of thermal cycle annealings. The longest minority carrier lifetime of GaAs on Si in this study is 0.38 ns, which is about one order of magnitude smaller than that of GaAs grown on the GaAs substrate under similar conditions. The minority carrier lifetime is increased as the dark-spot defect density is decreased.