Photoluminescence (PL) and photoluminescence excitation (PLE) spectroscopy of ZnSe1-xTex crystals has been investigated. At low Te concentration, x = 0.005, a free exciton peak as well as a broad emission band having phonon structure are observed in the PL spectra. The intensity of the free exciton luminescence increases with increasing temperature up to 50 K and above this temperature it decreases, while that of the blue band decreases monotonically. These features are interpreted in terms of the extrinsic self-trapping of excitons induced by Te atoms. In particular, the temperature behavior of the luminescence is explained by the back transfer of excitons from a self-trapped state to a free exciton state. The results are discussed by using configurational coordinate diagrams.
Bibliographical noteFunding Information:
This work was fully supported by Ministry of Education of Korea through ISRC.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Inorganic Chemistry
- Materials Chemistry