Sb₂Se₃ Nanosheet Film-Based Devices for Ultraviolet Photodetection and Resistive Switching

The development of multifunctional devices could represent a significant advancement in meeting the need for nano and micro technologies. Therefore, we have developed a Ag/Sb 2 Se 3 /FTO-based multifunction device having nanostructures, which works as an ultraviolet (UV) photodetector and a switching device. Our theory suggests how oxygen formation leads to detection in the UV range rather than detection in the infrared range, which is the natural detection range of Sb 2 Se 3 . The m–s–m photodetector device is based on the photoconductive phenomenon, and ultrafast transient absorption spectroscopy has been extensively used to investigate the charge carrier dynamics of Sb 2 Se 3 films of 500 nm. At two distinct excitations, 375 nm UV and 532 nm visible light, and a pulse energy of 1 J per pulse, the effect of annealing on the charge carrier relaxation of the films was investigated. The kinetics of the hot charge carrier’s decay and recombination were studied for both as-grown and annealed films. The proposed theory is analyzed with the help of X-ray photoelectron spectroscopy and density functional theory studies. The device shows external quantum efficiency values of 2.9 and 1.3 at 375 and 386 nm, respectively. The rise time to fall time ratio was 0.29/0.30 s at 375 nm irradiation at 2 V bias at a power density of 32 mW/cm 2 . The same device shows bipolar resistive switching, in which resistance shifts from a high resistance state to a low resistance state in a voltage sweep from −1 to 0 V and then 0 to 1 V. The result of the switching phenomenon is reasonably justified by the electrochemical metallization phenomenon. An outstanding accomplishment in electronic devices is combining two different features on a single device.