Excitonic lasing of strain-free InP(As) quantum dots in AlInAs microdisk

Abstract

Formation, emission, and lasing properties of strain-free InP(As)/AlInAs quantum dots (QDs) embedded in AlInAs microdisk (MD) cavity were investigated using transmission electron microscopy and photoluminescence (PL) techniques. In MD structures, the QDs have the nano-pan-cake shape with the height of similar to 2 nm, the lateral size of 20-50 nm, and the density of similar to 5-10(9) cm(-2). Their emission observed at similar to 940 nm revealed strong temperature quenching, which points to exciton decomposition. It also showed unexpected type-I character, indicating In-As intermixing as confirmed by band structure calculations. We observed lasing of InP(As) QD excitons into whispering gallery modes in MD having the diameter of similar to 3.2 lm and providing a free spectral range of similar to 27 nm and quality factors up to Q similar to 13 000. Threshold of similar to 50 W/cm(2Y) and spontaneous emission coupling coefficient of similar to 0.2 were measured for this MD-QD system. Published by AIP Publishing