Growth of ZnS and ZnSSe by gas-source molecular beam epitaxy using hydride group VI sources

Abstract

ZnS and ZnSSe layers were successfully grown by gas-source molecular beam epitaxy using hydride H 2S and H 2Se sources, and their surface morphology was very smooth. The full width at half maximum of X-ray rocking curve of the ZnS x Se 1- x layer with S composition x of 0.06 (lattice-matching to a GaAs substrate) was as low as 22 arc sec. For the ZnSSe layer, the electron concentration was controlled in a 10 17 cm -3 range by using n-type dopant gallium, and a net acceptor concentration of 7.4 × 10 17 cm −3 was obtained by using active-nitrogen as p-type dopant. Using n- and p-ZnSSe layers, separate-confinement-heterostructure multiple-quantum-well laser diodes were fabricated. Lasing operation was observed by injecting a pulsed current at 77 K.