INAS DOTS GROWN ON INP(001) BY DROPLET HETEROEPITAXY USING OMVPE

We have successfully obtained InAs dots on InP (001) by droplet hetero -epitaxy and observed room-temperature photoluminescence (PL) spectrum with a peak at around 1.6 mu m. Dependences of the surface morphology on the substrate temperature and on the trimethylindium (TMIn)-supply time were investigated. From atomic force microscopy (AFM), images of the samples prepared by varying the TMIn-supply time, a critical cove rage for supplied In to form droplets was found to exist between 1.5 m onolayers (MLs) and 3 hits. This result was confirmed by low-temperatu re PL measurements. At the TMIn-supply of 3 MLs, which was above the c ritical coverage, small dots of height approximate to 5 nm were formed with the density of 9.8x10(9) cm(-2). A PL spectrum of the sample gro wn using the same sequence followed by the growth of a 10 nm InP cap-l ayer, exhibited a 1.6 mu m emission, with a full width at half maximum (FWHM) of 150 meV at room temperature. (C) 1998 Elsevier Science S.A. All rights reserved.