The charge-state dependent structural stability of the O vacancy in α-quartz was determined by using first-principles total-energy calculations. It was found that neutral and positively charged O vacancies exhibited bistability, and that a spontaneous structural transformation occurred for doubly positively and doubly negatively charged states. The structural transformation introduced a new electron trap, and could lead to the degradation of thin films.

A.Oshiyama: Japanese Journal of Applied Physics - 2, 1998, 37[2B], L232-4