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 st rained layer superlattice and thermal cycle annealing grown by metalor ganic chemical vapor deposition (MOCVD) have been characterized by cat hodeluminescence (CL) and time-resolved photoluminescence (TRP). The c alculated TRP decay curve is investigated by changing the material par ameters (bulk lifetime and surface recombination velocity). The minori ty carrier lifetime of GaAs on Si has been determined by fitting the e xperimentally obtained TRP curve to the calculated one. The minority c arrier lifetime increases and the dark-spot defect density decreases w ith increasing number of thermal cycle annealings. The longest minorit y carrier lifetime of GaAs on Si in this study is 0.38 ns, which is ab out 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.