Studies on structural, optical, and photoelectric properties of CdS_(1-x)Se_x films fabricated by selenization of chemical bath deposited CdS films

摘要

In this paper, high-pholoxensitive CdS_(1-x)Se_x films arc synthesized by a two-step technique, which includes the chemical bath deposition of CdS films and a following selenization process. The structural, optical, and photoelectric properties of the CdS_(1-x)Se_x films were investigated. With the substitution of selenium for sulfur atoms, grain sizes of the as-prepared CdS_(1-x)Se_x films arc effectively enlarged and reach the scales of the films thickness when the sclenization temperature exceeds 450 ℃. With increasing the selenization temperature from 350 to 550 ℃, the band gaps of CdS_(1-x)Se_x films gradually decrease from 2.37 to 1.82eV. Under the co-action of the grain-size enlargement and band-gap decrease, the CdS_(1-x)Se_x films fabricated at 450 ℃ show very pronounced photosensitivity. Noteworthy, the ratio of photo to dark conductivity of the CdS_(1-x)Se_x film selenized at 450 ℃ reaches 1.1 × 10~5, suggesting a promising application potential in the photoelectric devices.