Optical investigations of InN nanodots capped by GaN at different temperatures

Abstract

InN nanodots capped with GaN for temperatures from 600 to 730 degrees C were investigated. While the dot emission intensity at 0.77 eV decreased with increasing capping temperature, two extra visible emission bands appeared around 2.37 eV (green band) and 2.96 eV (violet band). Furthermore, x ray diffraction shows that the 71.7 degrees and 70.2 degrees peaks were tentatively attributed to InGaN alloy with In fractions of 14.8% and 34.2%, respectively. Moreover, the near-field measurements helped reveal the regions of different emissions. The violet-band mapping showed a spatial distribution in contrast to nanodot distribution but the green band showed a uniform distribution that apparently reflects the capping induced InGaN alloy. (c) 2007 American Institute of Physics.