Extremely narrow photoluminescence from the ensemble of InAsP/InP quantum dots

We report a photoluminescence (PL) study of self-assembled InAsP quantum dots (QDs) formed on InP by As/P exchange reaction in the reactor of low-pressure metalorganic chemical vapor deposition. By varying the buffer surface morphology, we succeeded to resolve earlier observed broad emission between 1.2 and 1.35 μm. As a result, a double-peak feature with extremely narrow line at about 1.2 μm was observed in the PL from QDs formed on the undoped InP buffer layer. The temperature and excitation intensity dependence has been measured. We found that the PL line intensity does not depend on the temperature, when PL spectra exhibit state filling as the excitation is increased.