Temperature-dependent photoluminescence from patterned InAs quantum dots formed using metalorganic chemical vapor epitaxy

Abstract

We analyze temperature-dependent photoluminescence (PL) behavior of patterned InAs/GaAs quantum dots (PQDs) formed by selective area epitaxy using metalorganic chemical vapor deposition. The processing scheme, described here, yields an ensemble of electronically isolated PQDs with PL characteristics that significantly differ from self-assembled (SA) QDs since neither a wetting layer nor neighboring QDs are available for coupling. The isolated nature of the PQDs supports a non-Fermi (nonequilibrium) carrier distribution which yields very different PL characteristics compared to the Fermi (equilibrium) distribution of the SAQDs especially at temperatures > 100K. Thus, the PQDs demonstrate a constant PL linewidth within the temperature range of 80-300K along with improved temperature stability of PL intensity in comparison to SAQDs. The increased temperature stability allowed by electronic isolation may prove very important for high speed, temperature-insensitive QD laser development. © 2006 American Institute of Physics.