Defect engineering of titanium dioxide : full defect disorder

Titanium dioxide (rutile) is known as n-type semiconductor. Recent studies show that prolonged oxidation of pure n-type TiO2 may lead to its conversion into a p-type semiconductor. It has been documented that the conversion is associated with the formation of titanium vacancies. The present work derives the defect disorder model of TiO2, which explains the effect of oxygen activity on the concentration of all point defects, including titanium vacancies, and the related semiconducting properties. The derived defect diagram, plotting the concentration of all ionic and electronic defects in TiO2 within a wide range of oxygen activity [10-15 Pa