Crystal growth of nitride-rich GaNP by laser-assisted metalorganic chemical-vapor deposition

Abstract

The growth of GaNP using laser-assisted metalorganic chemical-vapor deposition (LA-MOCVD) was carried out for the fabrication of a light-emitting diode (LED). We used an Ar–F laser in order to decompose the source gases at lower temperature. Trimethylgallium (TMG), ammonia (NH 3) and tertiarybuthylphosphine (TBP) were used for the growth. GaNP growth was carried out at different temperatures. As a result, nitride-rich (N-rich) GaN 1− x P x could be grown at 850–950°C. The surface morphologies of GaNP were improved when the growth temperature was increased to above 900°C. We investigated the photoluminescence (PL) of GaNP at 77 K. The peak of band-edge emission shifted to about 0.2 eV compared with the GaN band-edge emission. The effect of laser irradiation during growth was investigated using a PL measurement. In the case of using laser irradiation, the band-edge emission of GaN 1− x P x was enhanced compared with the case of using no laser irradiation. Furthermore, a GaNP single quantum well (SQW) blue–violet LED was fabricated and the electroluminescence (EL) spectra were investigated. The bright band-edge emission at 425 nm was observed.