Many carrier effects in self-assembled InP quantum dots

Excitation power density dependence of InP self-assembled quantum dots (SAD s) was investigated under band-to-band excitation in a Ga0.5In0.5P matrix b y means of macro- (conventional) and micro-spectroscopy. State filling of c onfined excitonic states was studied in detail by micro-photoluminescence ( mu -PL) spectra and images. The efficiency of the state filling differs fro m dot to dot, which depends on the inflow and outflow rates of the excitons . Sharp mu -PL lines from a single confined exciton and biexciton were clea rly observed. The observed biexciton binding energy of an InP SAD is a few times larger than that of the bulk InP, suggesting that the multi-exciton s tates are stabilized because of the confinement. (C) 2001 Elsevier Science Ltd. All rights reserved.