Improvement Spectral Responsivity of TiO2 Nanoparticles via Pulsed Laser Deposition Deposited on Silicon Nanostructures

In the present work, we used a pulsed laser deposition technique to embed TiO 2 nanostructure on porous silicon substrates using a pulsed laser deposition process. Nanocrystalline porous silicon was synthesized using the photo-assisted electrochemical method. The study analyzed the optoelectronic characteristics of double junctions of TiO 2 /PS/n-Si structures as well as the PS/n-Si structure. We investigated the properties of TiO 2 /PS/n-Si and PS/n-Si structures, focusing on their structural, optical, and electrical features under ambient conditions. The XRD measurement indicated the formation of the anatase and rutile tetragonal phases with the preferred orientation anatase (101) plane in the prepared sample. The mean sizes of The TiO 2 nanostructures deposited onto porous silicon substrates range from 45.97 to 109.23 nm. The degree of pore filling depends upon the laser fluences employed, varying from moderate to close to complete packing. The optical properties of TiO 2 /PS/n-Si structures showed decreasing reflectance after depositing on porous silicon. The TiO 2 nanostructure produced on porous silicon exhibits five different spectra in the UV and visible range, as displayed in the room-temperature photoluminescence analysis. The current density–voltage characteristics of formed samples in dark and photoilluminated conditions are examined at room temperature. The properties of the TiO 2 /PS/n-Si structure enhance those of the PS/n-Si device. The highest specific detectivity of the TiO 2 /PS/n-Si devices is 32.45 × 10 10 Jones in the visible region, while the ultraviolet region is 30.04 × 10 10 Jones. The TiO 2 /PS/n-Si photodetectors possess an optimal relative quantum efficiency of 80.1% in the near UV region, whereas, in the visible range, the values of relative quantum efficiency are 51.8% at 531 nm and 54.5% at 634 nm. The findings reveal that formed photodetectors exhibit UV and visible light sensitivity after depositing TiO 2 layers on porous silicon. However, the photodetectors produced using TiO 2 nanostructures placed on porous silicon demonstrate greater sensitivity than those made from as-synthesized porous silicon.