First-principles study of native point defects in ZnGeP_2
Abstract
Ternary semiconductors with the chalcopyrite structure such as ZnGeP2 are attractive for frequency conversion nonlinear optical applications in tunable mid infrared laser sources because of their high second order optical response coefficients and birefringence which allows for phase matching. However, point defects with undesirable optical absorption bands are limiting the performance. In this paper, we present a computational study of native defects in ZnGeP_2. Using fully structurally relaxed full-potential linear muffin-tin orbital local density functional 64 atom supercell calculations, we obtained energies of formation as function of the Zn and Ge chemical potentials and as a function of the Fermi level for the various possible charge states of V_Zn, V_Ge, Zn_Ge,and Ge_Zn point defects. Our calculations indicate that previous interpretations of the EPR AL1 center as the V_Zn^- center need to be revised. Work supported by AFOSR.
- Publication:
-
APS Ohio Sections Fall Meeting Abstracts
- Pub Date:
- October 2003
- Bibcode:
- 2003APS..OSF..P005J