Photocurrent application of Zn-doped CdS nanostructures grown by thermal evaporation method

Abstract Undoped and Zn-doped CdS nanostructures were grown on Si/SiO 2 substrates by a thermal evaporation method in a tube furnace under Ar/H 2 gas atmosphere. Field emission scanning electron microscopy (FESEM) results showed a mix of belt and rod shaped with nano-sizes for the undoped CdS, while, the Zn-doped CdS sample had nanorods morphology. X-ray diffraction (XRD) patterns of two sets of the nanostructures indicated that these nanostructures had a CdS structure with a hexagonal phase. Evidence of dopant incorporation is demonstrated by X-ray photoelectron spectroscopy (XPS) of the Zn-doped CdS nanostructures. Room temperature photoluminescence (PL) and UV–vis spectrometers were used to study optical properties of the undoped and Zn-doped CdS nanostructures. Optical characterization showed that emission and absorption peaks were in the blue region of the electromagnetic spectrum for two samples. In addition, the optical studies of the Zn-doped CdS nanostructures revealed that the band gap of the Zn-doped CdS is bigger than the band gap of the undoped CdS nanostructures. Finally, the CdS nanostructures were used as photodetector by a blue light source under different bias voltage conditions. The photocurrent studies of the samples showed that, Zn-doped CdS nanostructures are better detector in comparison to the undoped CdS nanostructures.