In this article, we report direct evidence for efficient nonresonant two-photon absorption-induced luminescence in ZnO pellets at 2 K and room temperature. Stimulated emission near the band edge is observed at room temperature employing this form of excitation under low excitation levels over a broad range of excitation wavelengths. The steady-state population dynamics based on the time-integrated photoluminescence spectra at 2 K indicates that this nonresonant two-photon excitation is much more efficient in creating excitonic matter, compared with the traditional one-photon excitation method.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)