A study of the UV photodetectors properties based on the effect of TiO2 on ZnO nanorods grown via the chemical bath deposition method on p-type Si (100) substrates

Abstract

In this study, a heating composition process was used to construct Ti-doped ZnO (Ti/ZnO) nanocomposites to serve as an active layer in UV detection devices. Prior to synthesis, a ZnO seed layer was deposited on p-type Si (100) substrates (p-Si substrates) using radio frequency (RF) sputtering. Afterward, Ti/ZnO thin films (TFs) were successfully grown using the chemical bath deposition method (CBD) by combining different amounts of TiO2 nanofluid with ZnO precursor solutions. The volume of the TiO2 nanofluid ranged from 12.5% to 50% with respect to the total volume. FE-SEM, EDX, and AFM were employed to examine the morphological, elemental, and topographical characteristics of the formed nanocomposites. Thermo-evaporation was used to print Ag interdigitated electrodes (IDE) on the nanocomposites to fabricate UV photodetectors. The (002) Ti/ZnO peak along the z-axis on the substrate, which increases with increasing amounts of TiO2, provides evidence of the crystallinity and the hexagonal wurtzite structure of the samples. UV–Vis spectroscopy showed high diffuse reflectance curves with indirect energy bandgaps from 3.1969 eV to 3.2203 eV. The TiO2 nanofluid used in the growth impacted the synthesized Ti/ZnO, which affected the performance of the photodetectors. A responsivity, photosensitivity, gain, detectivity, rise time, and decay time of 0.107495 AW−1, 3833.67%, 39.34, 6.75 × 108 jones, 0.19 s, and 0.24 s were recorded when 50% of the TiO2 was used during the synthesis process of the ZnO nanorods. Based on the findings, the nanocomposites grown on p-Si substrates are suitable for use as thin films in optoelectronics, especially UV detection devices.