Enhancing UV photodetection sensitivity via pulsed laser optimization in SnO2:WO3/Si nanostructures

Abstract This manuscript investigates the deposition of tin oxide (SnO 2 )-doped tungsten trioxide (WO 3 ) films on silicon (Si) substrate using a pulsed laser deposition technique for ultraviolet (UV) photodetection. The structural, optical, morphological, electrical, and photodetector properties of SnO 2 -doped WO 3 films were extensively investigated. The optical characteristics, studied using UV–vis spectroscopy, reveal a tunable optical bandgap ranging from 2.85 eV to 2.25 eV with increasing laser energy, which is consistent with the findings obtained from photoluminescence analysis. Raman spectroscopy demonstrates three vibration modes at 319.80, 603.30, and 866.20 cm −1 . Field emission scanning electron microscopy images display spherical nanoparticles with average diameters of 43.90, 47.55, and 62.20 nm for 140, 180, and 220 mJ, respectively. Atomic force microscopy (AFM) measurements indicate an increase in the thin film grain size, roughness surface, and root mean square at higher laser energies (140, 180, and 220 mJ). Under illumination conditions, the photodetector gives a considerable amount of photocurrent (0.5 mA), which increases with higher laser energies. The proposed geometry demonstrates an excellent photo-response within a wavelength range of 350–550 nm, mainly at 420 nm. The optimized device illuminated with a laser energy of 220 mJ exhibits a response and recovery time of 352 ms and 737 ms, respectively, highlighting its potential for efficient and responsive applications.