IR Materials Producibility
Quarterly rept., no. 2, 1 Nov 1992-31 Jan 1993
SRI INTERNATIONAL MENLO PARK CA
Pagination or Media Count:
We have begun the calculation of relaxation of the near neighbors about the native defects in HgCdTe. We have found that approximate self- consistent schemes are inadequate for the large displacements of the highly strained defects, and therefore these calculations are being done self- consistently. The fields produced by long-range strain fields of dislocations via the piezoelectric effect and charged dislocation cores have been calculated for HgCdTe. The impact of dislocation core charges depends on the location of the dislocation and is greater in the depletion region where the screening is reduced, and smaller in the neutral regions of the device. We also find that their impact decreases as the temperature is increased. We have completed the calculations of the unrelaxed native point defect energies in ZnSe within the local density approximation and have begun the calculation of the gradient correction to these energies. Based on these preliminary numbers, we predict the zinc vacancy and the zinc antisite, and the zinc interstitial to be the dominant defects in ZnSe. We are currently calculating the relaxation about the most important defects in ZnSe.... native point defect defect density photonic material IRFPA dislocation HgTe CdTe ZnSe HgCdTe.
- Electricity and Magnetism