Efficient free exciton emission at room temperature in Zn0.5Cd0.5Se/MgxZnyCd1KxKySe quantum wells
نویسندگان
چکیده
We use temperature and power-dependent photoluminescence spectroscopy to demonstrate efficient free exciton emission at room temperature in high quality, strongly confining Zn0.5Cd0.5Se/MgxZnyCd1KxKySe quantum wells. Our measurements indicate that at low temperatures (T!50 K), the luminescence is dominated by bound exciton emission. However, free exciton emission becomes dominant at high temperatures (TO100 K) and persists up to room temperature with an intensity that is w40% that at cryogenic temperatures. We attribute these observations to the deep confinement potential that stabilizes excitons and prevents their thermal escape. q 2004 Elsevier Ltd. All rights reserved. PACS: 71.35.Cc; 71.55.Gs; 78.55.Et
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