Absorption and reflectivity measurements have been carried out for Zn1
-xCdxSe:Ni and ZnSxSe1-x:Ni solid solutions. Energy level positions of
nickel 2+/1+ charge state have been used for estimation of band offse
ts for the valence and conduction bands of ZnCdSe/ZnSe and ZnSSe/ZnSe.
Intra-shell transitions of Ni2+ were also studied.