Abstract
Continuous-wave, time-integrated, and time-resolved photoluminescence experiments are used to study the excitonic optical recombinations in wurtzite quantum wells of varying widths. By comparing experimental results with a variational calculation of excitonic energies and oscillator strengths, we determine the magnitude of the longitudinal electric field that is induced by both spontaneous and piezoelectric polarizations. The quantum-confined Stark effect counteracts quantum confinement effects for well widths larger than , leading to emission energies that can lie below the ZnO excitonic gap and to radiative lifetimes that can be larger than milliseconds.
- Received 5 October 2005
DOI:https://doi.org/10.1103/PhysRevB.72.241305
©2005 American Physical Society