1. Pressure behavior of Te isoelectronic centers in S-rich ZnS1xTex alloy
- Author
-
Hexiang Han, W. K. Ge, B. S. Ma, Guijiang Li, Iam Keong Sou, Kun Ding, Fuhai Su, and Z. L. Fang
- Subjects
Photoluminescence ,Condensed matter physics ,Band gap ,Chemistry ,Exciton ,Alloy ,Hydrostatic pressure ,Analytical chemistry ,engineering.material ,Condensed Matter Physics ,Pressure coefficient ,Electronic, Optical and Magnetic Materials ,Impurity ,engineering - Abstract
The photoluminescence from ZnS1-xTex alloy with 0 < x < 0.3 was investigated under hydrostatic pressure up to 7 GPa. Two peaks were observed in the alloys with x < 0.01, which are related to excitons bound to isolated Te isoelectronic impurities (Te-1 centers) and Te pairs (Te-2 centers), respectively. Only the Te-2 related emissions were observed in the alloys with 0.01 < x < 0.03. The emissions in the alloys with 0.03 < x < 0.3 are attributed to the excitons bound to the Te-n (n greater than or equal to 3) cluster centers. The pressure coefficient of the Te-1 related peak is 89(4) meV/GPa, about 40% larger than that of the band gap of ZnS. On the other hand, the pressure coefficient of the Te-2 related emissions is only 52(4) meV/GPa, about 15% smaller than that of the ZnS band gap. A simple Koster-Slater model has been used to explain the different pressure behavior of the Te-1 and Te-2 centers. The pressure coefficient of the Te-3 centers is 62(2) meV/GPa. Then the pressure coefficients of the Te-n centers decrease rapidly with further increasing Te composition.
- Published
- 2003