Abstract
The nonlinear variation of the fundamental energy gap as a function of composition x observed in chalcopyrite-structure alloys is discussed. The downward optical-bowing parameter scrc observed in these alloys is analyzed in terms of current models given in the literature. A relationship between scrc and the difference in electronegativities ΔX of the atoms mixed to form the alloy is obtained. Also, an expression to predict the vs-x curve for these alloys is proposed and good agreement with experimental data is found.
- Received 19 February 1991
DOI:https://doi.org/10.1103/PhysRevB.44.1613
©1991 American Physical Society