Morphology-tuned Fe-doped Cu2SnS3 via Microwave synthesis for Efficient Zero-Bias Photodetection

Abstract

A self-biased broadband Fe-doped Cu₂SnS₃ photodetector has been fabricated using the microwave irradiation technique, which is prepared using three different solvents 2-phenoxyethanol (2PE), ethylene glycol (EG), and polyethylene glycol-200 (PEG-200). Here, the most important parameter that affects the photodetective behavior, such as structural, morphological, and optical properties, was analysed by a thorough understanding of nucleation kinetics and particle size distribution correlated with solvent polarity. The charge carrier dynamics of the device have been studied using the SCAPS-1D simulation software for the device configuration FTO/Fe-doped CTS/Al, through electron/hole generation rate, built-in electric field, which also leads to generate energy band diagram for the performance of the photodetector. The particle synthesized in 2PE shows doughnut morphology and EG, PEG shows the spherical morphology with varied particle size, which also accelerated phase formation and defect passivation, improving photoresponse dynamics, exhibiting remarkable specific detectivities of 7.07×10⁹ Jones (2PE), 3.504×10¹⁰ Jones(EG), and 9.58×10¹⁰ Jones (PEG-200) under 1Sun illumination, with fast response and recovery times in high on/off ratios. These findings elucidate solvent-microwave synergies for scalable chalcogenide synthesis, advancing high-performance optoelectronics.