The absorption spectrum of NI2+(d8) in GaP

Abstract
A new absorption band was found in compensated GaP:Ni:S crystals near 0.8 eV. Optical investigations of the nickel diffusion profile in GaP:Ni proved that this band is associated with the isolated Ni2+(d8) centre. The interpretation of the 0.8 eV band as being due to the 3T1(F)-3T2(F) crystal-field transition is suggested.