Characterization of photoconductive CdS thin films prepared on glass substrates for photoconductive-sensor applications

Cadmium sulfide (CdS) thin films with n -type semiconductor characteristics were prepared at room temperature on glass substrates by radio-frequency magnetron sputtering for photoconductive-sensor applications. Films deposited at room temperature exhibit polycrystalline phases and show smooth surface morphologies. The deposition rate of the films decreases with increasing working pressure. The dark- and photoresistances in 400 - nm -thick CdS films deposited at 6.7 × 10 − 1 Pa and 80 W were approximately 1 × 10 5 and 3 × 10 4 Ω ∕ sq , respectively. Lowering both the dark- and photoresistances lowers the sensitivity ( R dark ∕ R photo ) of the resistance.