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/MgxZn yCd1-x-ySe 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 (T> 100 K) and persists up to room temperature with an intensity that is ∼40% that at cryogenic temperatures. We attribute these observations to the deep confinement potential that stabilizes excitons and prevents their thermal escape.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Materials Chemistry