Preparation of CdS and Se/SeO₂ by laser ablation for Photodetector Applications

This work describes the successful synthesis of Cadmium sulfide and selenium nanoparticles using pulsed laser ablation in liquid (DW). The analysis of the morphological structural, optical, and chemical properties of all samples has been conducted. From XRD, it found the Se, SeO2 and Se2O5 phases with average Crystalline size 10.84 nm and 19.37 nm, respectively. By FE-SEM of CdS and Selenium/Selenium Oxide was used to study the morphologies of the films, where The particles diameters was 90.89 nm. and 50.51 nm respectively. Using atomic force microscopy (AFM)of CdS and selenium/selenium oxide films were found to have average grain sizes of 40.14 and 32.07 nm, respectively. CdS nanoparticles have a band gap of 2.5 eV, while selenium/selenium oxide was discovered to have a band gap of 4.49 eV. The vibrational and functional groups found in the CdS and Selenium/Selenium oxide system have been studied by recording the FTIR spectra of CdS and Selenium/Selenium oxide NPs at room temperature. This work also describes the design of three common CdS/Si (D1), Se-Selenium oxide/Si (D2), and Se-Selenium oxide/CdS/Si(D3) Heterojunction photodetectors. The D1 detector's response spectrum shows good selectivity for VIS and NIR light detection. For optoelectronic applications, CdS NPs could therefore be a promising candidate material. It was discovered that case D2 exclusively responds to NIR light. In contrast, D3 has a reaction to both visible and infrared light.