The defect centers responsible for both the shallow and deep level emissions commonly seen in the photoluminescence spectra of high purity vapor phase epitaxially grown ZnSe have been investigated. The donor-acceptor pair emission at 2.681 eV has been associated with hole traps at 90 and 130 meV above the valence band edge as measured by optical transient capacitance spectroscopy. From the analysis of low temperature photoluminescence the traps are attributed to sodium. Photoluminescence emission at 1.94 eV has been correlated with a deep level at Ec- 2.25 eV as observed by steady state photocapacitance spectroscopy. Electron irradiation of the ZnSe thin films support the association of the defect centers responsible for 1.94 eV emission with the self-activated complex.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics