Is 242 nm absorption band connected to an oxygen vacancy in Ge-doped silica glass?

摘要

The oxygen vacancy is one of the defects very often called for the interpretation of the UV absorption spectrum and particularly to explain the 242 nm absorption band. Other defects like twofold coordinated silicon or germanium atom are also considered. The method for computing theoretically the absorption spectrum must first be validated. In this respect, it is valuable to compare formation energies obtained with different approaches and then with the temperature dependence of the 242 nm absorption band. This is the purpose of this paper.