Emission of Self Assembled CdTe/ZnTe Quantum Dot Samples with Different Cap Thickness

S. Nowaka, T. Jakubczyka, M. Gorycaa, b, P. Ciosmaka, A. Golnika, P. Kossackia, b, P. Wojnarc and J.A. Gaja a Institute of Experimental Physics, University of Warsaw, Hoża 69, 00-681 Warsaw, Poland b Grenoble High Magnetic Field Laboratory, CNRS, Grenoble, France c Institute of Physics, Polish Academy of Sciences, al. Lotników 32/46, 02-668 Warsaw, Poland

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Photoluminescence measurements on CdTe/ZeTe self-assembled quantum dot samples with different cap thickness values (18-110nm) were performed at 1.8 K at varying excitation levels. The shape of macrophotoluminescence spectra did not altered notably with the excitation power. The spectra exhibited interference fringes related to the total barrier thickness. Simulation of the fringes confirmed the barrier thickness determined during the growth. The minimal amplitude of the fringes was observed for the cap thickness corresponding approximately to a quarter of the emission wavelength in the barrier material. Maximum emission intensity occurred for the largest thickness of the cap, i.e., 110 nm. We attribute this result to the influence of the surface recombination centers.

DOI: 10.12693/APhysPolA.116.890 PACS numbers: 78.55.Et, 78.67.Hc