Molecular-beam epitaxy growth of II–VI light-emitting devices on GaAs substrates using valved sources for S and Se

Abstract

II–VI light-emitting devices containing quaternary (ZnMgSSe), ternary (ZnSSe, ZnCdSe, ZnTeSe), and binary (ZnTe, ZnSe) epilayers have been successfully grown on (100) GaAs substrates by molecular-beam epitaxy (MBE) using valved sources specially designed for elemental S and Se, respectively. Use of S and Se valved sources permits the rapid adjustment of alloy compositions for lattice-matching of Zn1−xMgxSySe1−y and ZnSzSe1−z epilayers to GaAs as is needed for growth of light-emitting diode and laser diode structures. Flux measurements have shown that these valved sources are stable for time periods necessary for MBE growth of these II–VI device structures. Secondary ion mass spectroscopy analysis has shown that B contamination level, a major problem in earlier valved-source designs, is below the detection limit of the instrument in the II–VI epilayers grown by MBE using the present S and Se valved sources. Blue and green light-emitting diodes and room-temperature pulsed laser diodes have been successfully synthesized using the valved sources.