Fabrication and SILAR cycle-dependent characterization of CdS/p-Si heterojunction photodetector

Abstract

We report the fabrication CdS/p-Si heterojunction via a successive ionic layer adsorption and reaction (SILAR) technique with different CdS thickness controlled by SILAR cycles. A brief investigation has been carried out to study the nano-structural, photodetecting and optical characteristics of prepared CdS/p-Si heterojunction. Structural and morphological characterizations confirmed the formation of crystalline hexagonal CdS thin films with nano-sized grain particles that develops closed packed with SILAR cycles. Photoluminescence (PL) have been studied that emission peak at 472 nm associated with excitonic emission and a broad green emission peak positioned at 553 nm from the recombination of S−2 vacancy with valence band of CdS film. Current–voltage (I–V) and optoelectronic properties of prepared samples presented the rectification properties having the ideality factor more than unity, while the peaks of response have two peaks located at 450 and 800 nm with maximum responsivity at 6 SILAR cycles.