Optical Absorption of Bi_(12)SiO_(20):M (M = Cr, P, Cr+P)

摘要

The spectral distribution of the optical absorption coefficient is studied in un-doped Bi_(12)SiO_(20) (BSO) crystals and in such doped with Cr and P and co-doped with (Cr~+P~(5+)). The inclusion of donors (Cr~(3+)) changes markedly the optical absorption coefficient, while the inclusion of acceptors (P~(5+)) much more weakly even in higher concentrations. A Gauss decomposition of the spectra allowed one to determine values for the energy position and the width of the impurity levels arising upon doping. The data indicate the incorporation of Cr in several oxidation states.