PHOTOLUMINESCENCE DECAY MEASUREMENTS OF ZNSXSE1-X (0-LESS-THAN-X-LESS-THAN-0.12) EPILAYERS ON GAAS SUBSTRATE GROWN BY MOLECULAR-BEAM EPITAXY

The steady-state and time-resolved photoluminescence (PL) studies of Z nSxSe1-x epilayers on GaAs substrate grown by molecular beam epitaxy a round the lattice matching composition (0 < x < 0.12) are discussed. W e have investigated the PL decay dynamics of ZnSxSe1-x epilayers and f ound that the decay time of the ZnSxSe1-x epilayer with sulfur composi tion closely lattice-matched with the substrate is longer than that of any other sample. This finding is interpreted as indicating that the defects induced by lattice mismatch act as nonradiative recombination centers and consequently reduce the PL lifetimes of the epilayers. The se studies suggest that the lattice mismatch has a strong correlation with PL lifetimes of the ZnSxSe1-x epilayers. (C) 1997 Elsevier Scienc e Ltd.