Tuning doping site and type by strain: Enhanced -type doping in Li doped ZnO

Using the first-principles method, we show that the preference of substitutional and interstitial doping can be tuned through external strain, either hydrostatic or epitaxial, because doping induces a volume change around the dopants. When the external strain is applied in the same direction as the volume change, the solubility is enhanced. As an example, we show that Li substitution on Zn sites in ZnO, which is desired for p -type doping, can be enhanced against the Li interstitial doping, which passivates the p -type doping. We suggest that this general strategy should be very useful to control doping of many semiconductor materials.