Enhanced photodetection performance of silver-doped tin sulfide photodetectors for visible light photodetection

• Published in: Sensors and actuators. A. Physical. 2023-01, Vol.349, p.114065, Article 114065
• Main Authors: Alagarasan, Devarajan, Varadharajaperumal, S., Aadhavan, R., Shanmugavelu, B., Naik, R., Kh, Salunii, Haunsbhavi, Kumar, Shkir, Mohd, El Sayed Massoud, Ehab, Ganesan, R.
• Format: Article
• Language: English
• Subjects: Ag doping; Optical properties; Photodetector; SnS thin film; Thermal evaporation technique
• ISSN: 0924-4247; 1873-3069
• DOI: 10.1016/j.sna.2022.114065

SnS and Ag doped (0.5, 1.0, 1.5, and 2 at%) SnS thin films were fabricated using thermal evaporation method for application in light detecting devices. X-ray diffraction (XRD) confirmed the polycrystalline character of all produced films, and it was found that all samples crystallised into the orthorhombic crystal structure. In all of the produced films, Raman spectra clearly displays the peaks associated with the SnS phase. Field emission scanning electron microscopy (FESEM) images reveals that the crystallites are arranged in a nanosheet-like pattern. Energy dispersive spectroscopy (EDS) confirmed the existence of Sn, S, and Ag elements, as well as their stoichiometry, in the as-deposited film. The optical bandgap values were observed to rise up to 1.5 at% of Ag in SnS, after which more Ag in SnS decreases the bandgap. Photo-sensing measurements revealed that sensing qualities enhanced for Ag-doping in SnS thin films up to 1.5 at% Ag and then reduced for 2 at% Ag. The highest levels of responsivity (R), external quantum efficiency (EQE), and detectivity (D*) were attained with 1.5 at% Ag-doped SnS, with R, EQE, and D* values of 1.32 × 10-1AW, 31 %, and 4.77 × 109 Jones, respectively. The improved phtodetection performance might be explained by a decrease in charge carrier recombination rates and grain size modification to the right size. [Display omitted] •SnS and Ag doped (0.5, 1.0, 1.5, and 2 at%) SnS thin films were fabricated using thermal evaporation method.•The Ag doped SnS thin films having orthorhombic structure and the films exhibit columnar plate-like grain morphology with different widths and thicknesses.•The energy band gap value was found in the range of (1.35–1.67 eV).•The Ag-SnS (1.5%) photodetector exhibited the best photodetection performance.