Flexible and Broadband Photodetectors via Solution Processed Antimony Selenide

The demand for high-performing low-cost broadband photon detection has generated interest in new materials that couple high absorption with traditional electronic infrastructure (CMOS) compatibility. In this study, we demonstrate a facile, low-cost and scalable, catalyst-free one-step solution-processed approach to grow one-dimensional Sb$_{\mathrm{2}}$Se$_{\mathrm{3}}$ nanostructures directly on flexible substrates for high-performing near infrared (NIR) photodetectors. Structural characterization and compositional analyses reveal high-quality single-crystalline nanowires with orthorhombic crystal structure and a near-stoichiometric atomic ratio of antimony to selenium (Sb: Se). A measured direct band gap of 1.12 eV is consistent with predictions from theoretical simulations, indicating strong NIR potential. Metal-semiconductor-metal photodetectors fabricated from this material exhibit fast response (on the order of milliseconds), high performance (responsivity \textasciitilde 0.27 A/W), outstanding mechanical flexibility, and structural durability. The experimental results demonstrate the potential of solution-processed Sb$_{\mathrm{2}}$Se$_{\mathrm{3}}$ nanostructures in flexible and broadband optoelectronic devices.