The light detection in the broadband ranging from ultraviolet to near infrared regime has engrossed substantial attention owing to several applications such as environmental monitoring, optical communication, spectral switching, infrared imaging and memory storage. In this work, we have used WO3 metal oxide semiconductor in the nano particle (NP) state with a wide bandgap as well as higher optical absorption coefficient presenting pronounced potential in the broadband (300¿1100¿nm) photodetection field. The prepared cost-effective Ag/WO3NPs/p-Si heterojunction photodetector (PD) devices were successfully interpreted by I-V data in dark/illumination, EQE, D*, responsivity and NEP as a function of annealing process. At 3¿V bias, the superior photosensing parameters such as responsivity of 3261¿A/W, specific detectivity of 3.1×1015- 9.7×1015 Jones and EQE of 2.1×105-4.7×105% were achieved. At 0¿V, the 500 ¿ PD device exhibited superior (Formula presented) values of 810 ms/680 ms at 370 nm and 260 ms/380 ms at 1000 nm light illumination. Acetone was used as the target analyte to evaluate the gas sensing capabilities at 200 and 300 °C under variable flow rates (60¿300 sccm) using nitrogen as a carrier gas; among the post-annealed samples, the 700 °C device exhibited the highest sensing response (74%) and the fastest dynamics, reaching response/recovery times as low as 15/45 s. Thus, our present work sheds light on the notable potential of Ag/WO3NPs/p-Si heterojunctions in the field of broadband photodetection as well as acetone gas sensing.
