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Metal chalcogenides have recently gained intensive attention due to their tunable bandgap energy, optoelectronic characteristics, and exceptional optical absorption. Because of the potential advantage of photodetectors, photovoltaic, holographic recording systems, and field-effect transistors, bismuth tri-sulfide (Bi2S3) crystals, in particular, have attracted a lot of focus in scientific research. In this study, the low-cost nebulizer spray technique was employed to synthesize the proposed Bi2S3:Sn thin films on glass substrates, varying the Sn doping concentrations in Bi2S3 films (from 1 to 3%). The crystallites of the orthorhombic-structured polycrystalline Bi2S3 films were all oriented in the same direction (130). According to the XRD spectra, preferred orientation and crystalline quality were improved by Sn doping concentrations up to 2%, but, above 2% of the Sn doping ratio, the structural properties were decreased. With increasing Sn-doping levels, the estimated direct band gap (Eg) of the Bi2S3:Sn films decreased, reaching a low value of 2.01 eV at 2% Sn and then rising. A field emission scanning electron microscope (FESEM) was applied to determine the size and shape of the grains in prepared Sn: Bi2S3 films.The 2% Sn-doped Bi2S3 thin film may be more appropriate for high-speed optoelectronic devices due to its high responsivity (1.24 AW−1), external quantum efficiency (40%), and detectivity properties (1.83 × 1010Jones). A potential mechanism for photodetector performance in the presence of air and UV radiation was also discussed in the present work for the proposed Sn: Bi2S3 thin films.

We report co-doping effects of transition metal elements (Ni, Co) primarily on the opto-electronic properties of CuO thin films. CuO, CuO:Ni(1%), CuO:Co(1%) and CuO:Ni(1%):Co(1%) thin films were deposited via the spray pyrolysis route. Structural studies revealed the monoclinic CuO structure for all films. For all the films scanning electron microscope (SEM) images showed a crack-free and homogeneous surface. Photoluminescence (PL) spectra of all the films exhibited four emission peaks at 415, 451, 477, and 521 nm wavelengths. The optical bandgap (E g) values were around 2.12 eV, 2.18 eV, 2.05 eV and 1.84 eV for CuO, CuO:Ni(1%), CuO:Co(1%) and CuO:Ni(1%):Co(1%)thin films, respectively. CuO:Ni(1%):Co(1%) photo-device displayed a large responsivity (R) of 0.43 AW−1, external quantum efficiency (EQE) of 100% and detectivity (D *) of 9.55 × 109 Jones. Hence, co-doping of transition metal elements would be one of the effective approaches for enhancing opto-electronic properties of metal oxide compounds.