Electron mobility limited by correlated donors in hydrogen-bombarded ZnO surface quantum wells

We present a theory of the donor-limited mobility of a two-dimensional electron gas (2DEG) in a hydrogen-bombarded ZnO surface quantum well (SFQW), taking adequate account of high-temperature ionic correlation during thermal treatment and dependence of the effective electron mass on 2DEG density as well. In contrast to the existing theories, we derived a form factor less than unity, which properly describer the correlation effect. The effect is increased with an increase of the sheet donor density and decrease of the quenching temperature for donor diffusion. The donor scattering is found to be remarkably diminished by their correlation. As a result, the low-temperature mobility of the 2DEG in ZnO SFQWs is dominated by surface roughness scattering rather than the donor one. The numerical results are given to illustrate our theoretical conclusions. (author)