Structural, optical and electrical properties of AgBiS2 thin films for optoelectronic applications
摘要
Silver bismuth sulphide thin films were deposited on glass substrates by the dip coating technique using glycine as a complexing agent. Structural, morphological, compositional, optical, electrical, and thermoelectric properties were investigated using X-ray diffraction, scanning electron microscope, atomic absorption, optical absorption, electrical conductivity, and thermoelectric measurements. X-ray diffraction analysis confirmed the formation of polycrystalline AgBiS₂ with a cubic crystal structure. The preferential growth observed along (200) plane. The average crystallite size was estimated to be 41 nm. Scanning electron micrographs revealed a dense surface morphology composed of elongated needle like grains arranged in grass or flower like structures, indicating uniform coverage and good intergrain connectivity. Compositional analyses demonstrated that the deposited films were nearly stoichiometric. Optical absorption measurements indicated a direct optical band gap of approximately 1.33 eV. Electrical conductivity studies performed over a range of temperatures showed conductivity values between 5 × 10–5 and 7.31 × 10–2 (Ω·cm)⁻1, confirming semiconducting behavior. Thermoelectric measurements show the carrier concentration in the range of 2.564 × 1018 to 2.11 × 1019. This support the potential of AgBiS₂ thin films for optoelectronic and energy related applications for advanced device.