The relationship of the electrical contact between metal and CdS to the piezoelectric properties was investigated. The influence of the base metal on the crystallographic orientation of the CdS film and the nature of the electrical contact is demonstrated. By measurements of capacitance andI–Vcharacteristics, gold is shown to produce a Schottky barrier and aluminum an Ohmic electrical contact with CdS thin films. The effect of the depletion layer generated by the Schottky barrier on the acoustical output of CdS transducers is shown.