A process for controlling fractionation in selenium alloys comprising providing pellets of an alloy comprising amorphous selenium and an alloying component selected from the group consisting of tellurium, arsenic, and mixtures thereof, the particles having an average particle size between about 300 micrometers and about 3,000 micrometers, exposing the pellets to an ambient temperature of between about 114.degree. C. and about 190.degree. C. until an exotherm occurs in the pellets resulting in substantially complete crystallization between about 104.degree. C. and about 180.degree. C., grinding the pellets into fresh powder having an average particle size of less than about 200 micrometers, and compressing the fresh powder into fresh pellets having an average weight between about 50 mg and about 1000 mg. The resulting fresh pellets may be heated in a vacuum chamber to vacuum deposit the alloy onto a substrate.