Narrow photoluminescence peaks from localized states in InGaN quantum dot structures

Microscopic photoluminescence spectra were measured for self-assembled InGa N quantum dots (QDs) grown by metalorganic chemical vapor deposition. A thi n aluminum layer with 400 nm square apertures was formed on the sample surf ace to reduce the number of QDs measured. We observed very sharp peaks whos e spectral linewidths were typically 170 mu eV at 3.5 K, the linewidth bein g limited by spectral resolution. Such sharp lines were not observed in sim ilar experiments on a reference sample having single InGaN quantum well str ucture. These experimental results suggest that excitons are strongly confi ned in our InGaN QD structure. (C) 2000 American Institute of Physics. [S00 03-6951(00)02817-5].