SPIN SPLITTING OF DONOR-BOUND EXCITONS IN ZNO DUE TO COMBINED STRESS AND SPIN-EXCHANGE

There is a marked difference in the growth habits of ZnO crystals grow n from ZnSe and ZnS starting materials. Since selenium has a higher bo iling point than sulfur and the reaction takes place at lower temperat ures when the crystals are grown from ZnSe, the selenium may interact with the growing surface. This may be a cause for residual strain in t he ZnO crystals grown from ZnSe starting material. The residual strain is observed as spin splittings of the donor-bound exciton transitions . A fourfold splitting is observed due to a combination of strain and spin exchange.