Midinfrared photoluminescence of InAsSb quantum dots grown by liquid phaseepitaxy

Photoluminescence in the 2-5 mum spectral region is reported from InAs1-xSb x quantum dots grown from the liquid phase at 580 degreesC on an InAs (100) substrate. Atomic force microscopy shows that coalesced quantum dots and t hen isolated quantum dots are formed with increasing Sb composition (x=0.2- 0.3) and strain. The 4 K photoluminescence of the isolated and coalesced qu antum dots was observed to peak in the midinfrared at 289 and 316 meV, (4.2 9 and 3.92 mum), respectively. These peaks are due to type II transitions a nd begin to quench at temperatures above 100 K as holes become thermally ac tivated out of the quantum dot confinement potential. (C) 2000 American Ins titute of Physics. [S0003-6951(00)04248-0].