Strategies for Sb2se3 and Sb2s3 Absorbers Based Thin Film Heterojunction Photodetectors and Photovoltaic Devices

Abstract

Antimony chalcogenides, particularly Antimony Selenide (Sb2Se3) and Antimony newlineSulfide (Sb2S3) have garnered remarkable attention as promising materials for optoelectronic newlineapplications due to their exemplary properties. This thesis work explores the growth, newlinecharacterization, and application of highly anisotropic Sb2Se3 and Sb2S3 thin films for newlinephotodetectors and photovoltaic devices, focusing on strategies to achieve optimal newlinefunctional layers and device performance. newlineA facile route involving reactive selenization of antimony films deposited on glass newlinesubstrates via thermal evaporation was employed to obtain [001] oriented Sb2Se3 thin films, newlinewhich is crucial for optimizing charge carrier transport. The resultant Sb2Se3 thin films were newlinecomprehensively characterized using X-ray diffraction (XRD), scanning electron newlinemicroscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX) to confirm phase newlinepurity and compositional homogeneity, elucidating the crucial role of selenization newlinetemperature in their formation. Optical analysis revealed a high absorption coefficient of newline~1.75×105 cm-1 with direct band gap values ranging from 1.23 eV to 1.20 eV. Due to these newlinefavorable properties, photocurrent of 143 nA at a 5V applied bias was observed in films newlineselenized at 375°C under AM1.5 G illumination conditions. newlineTo explore the photodetection properties of the prepared Sb2Se3 films, A n-Si/p- newlineSb2Se3 heterojunction was fabricated and investigated. A photocurrent of 3.18 × 10-6 A was newlineobserved with a responsivity of 1.54 × 10-4 A/W, detectivity values of 4.9 × 109 Jones and newlineon/off ratio of 5210 at zero applied bias and AM1.5 illumination conditions. The newlinephotodetector exhibited a reliable response even at a lower incident power density of 2 newlinemW/cm² under white light illumination. A comprehensive evaluation was conducted under newlinedifferent incident wavelength and self-biased conditions, to validate the broadband newlinephotoresponse capabilities of the detector. The results indicated the favorable prospects of newlineSb2Se3 thin films prepared via the seleniza