Influence of incorporation of samarium (Sm3+) on the structural and optoelectronic properties of In2S3 thin film for photodetector applications

Abstract

In the current work, pure In2S3 and different concentrations of In2S3: Sm thin films (1, 2, 3 wt%) were made using the affordable and scalable nebulizer spray pyrolysis process for evaluating their photodetector properties at room temperature. For the purpose of examining their crystallographic, morphological, elemental, optical, and photo-sensing properties, the synthesized samples were examined utilizing a variety of analytical techniques. According to XRD analysis, the cubic phase of In2S3 with a dominating peak around the plane (400) that rises with the addition of Sm dopants in In2S3 thin films. The In2S3:Sm2% thin film had the largest crystallite size, measuring 59 nm. The results of the FESEM examination revealed that the non-uniform homogeneous tiny rocky crystals morphology and minute voids present in all of the produced thin films. UV–Vis studies showed, all the produced thin films have their highest absorption in the UV region and the minimum bandgap value of 2.71 eV was observed for the In2S3:Sm (2 wt%) thin film. The film showed emission peaks around 470 nm and 530 nm in the PL spectra due to the sulfur vacancies and indium interstitials. The results of the photo sensing analysis indicated that the fabricated In2S3:Sm (2 wt%) thin film photodetector exhibits better R, D*, EQE, raise/fall time values of 2.06 × 10-1 AW−1, 1.72x1010 Jones, 66%, and 0.08/0.1 s, respectively, indicating the device is more suitable for commercial photodetector application.