The diode properties of reactively sputtered hydrogenated amorphous silicon Schottky barrier structures (a‐SiHx/Pt) have been investigated. We find a systematic relation between the changes in the open circuit voltage, the barrier height, and the diode quality factor. These results are accounted for by assuming that hydrogen incorporation into the amorphous silicon network removes states from the top of the valence band and sharpens the valence‐band tail. Interfacial oxide layers play a significant role in the low hydrogen content, and low band‐gap regime.