Fabrication of TiO2 nanoparticles/porous-silicon heterostructure photodetector for UV detection

Abstract

TiO2 nanoparticles/porous-silicon heterostructure (TiO2-NPs/P-Si) was successfully synthesized using laser-assisted chemical bath deposition (LACBD). We employed a laser of 465 nm in wavelength, output power of 1 W, and 20 min deposition time to grow TiO2 nanoparticles on porous silicon. The TiO2-NPs/p-Si films properties were characterized by using FESEM, EDX, XRD, and UV-Vis. The TiO2-NPs/P-Si/Ag photodetector device performance were examined by Keithley 2400. The I-V curve of the device was tested in dark and with UV light of 365 nm wavelength conditions. It’s I-V behavior shows a Schottky behavior in the range of − 5 V and 5 V, with strong responsiveness and excellent performance. When the device is exposed to UV light, the channel current increases drastically by 183% at + 5 V, giving rise to a pronounced photoresponse. Under UV light, the current was observed to rose from − 3.5 × 10−5 A to − 3.0 × 10−5 A at − 5 V reversed bias voltage. The current increases immensely from 1.5 × 10−5 A to 3.5 × 10−4 A at +5 V forward bias voltage. For the I-t behavior, bias voltages of 1.5 V, 3 V, 4.5 V and 6 V were used and the device responsivity at these voltages were calculated to be 0.15e-3A/W, 1.59e-3A/W, 2.05e-3A/W and 2.06e-3A/W, demonstrating a great sensitivity of 558, 1160, 758 and 458 respectively. Our findings proved that TiO2 np/p-Si/Ag based photodetector could be fabricated using inexpensive, quick, and simple LACBD and yielded an excellent electrical response and sensitivity for UV photodetection applications.