Detecting Ultra-Violet Radiation by Using Titanium Dioxide Nanoparticles

Abstract

In this paper sensitivity of chemically synthesized titanium dioxide (TiO<sub>2</sub>) nanoparticles to ultra-violet (UV) radiation is investigated. For this purpose three types of ultra-violet photodetectors were fabricated, one with as-synthesized TiO<sub>2 </sub> nanoparticles, another one with TiO<sub>2</sub> nanoparticles annealed at 600℃, and the third one with TiO<sub>2</sub> nanoparticles annealed at 800℃. In each case the annealing time duration was one hour. The photodetectors were fabricated on glass slides where on them a thin layer of fluorine doped tin oxide (FTO) was deposited by spray pyrolysis. The results show that all photodetectors are sensitive to UV radiation where the photodetectors fabricated from annealed TiO<sub>2</sub> nanoparticles are more sensitive than the photodetectors fabricated from as-synthesized TiO<sub>2</sub> nanoparticles

Chemical bath deposited ZnO thin film based UV photoconductive detector

“…Wide band gap material such GaN, ZnO, TiO 2 , GaP etc. is used to detect the UV radiation due to their special properties such as the band gap energy value of these materials lies in the UV region, with their thermal stability and radiation hardness [3][4][5][6][7]. Among all these materials ZnO based UV photodetector studied extensively because of their outstanding physical and chemical properties [8].…”

Experimental Investigation of Lubrication Film Formation at Start-Up of Smooth Surfaces

“…The width of the optical zone was obtained by linear extrapolation of their straight portion to 0 of the graphs of optical absorption (αhν) 2 and (αhν) 1/2 versus photons energy (hν) for direct and indirect transitions, respectively [Sreemany 2010, Kernazhitsky 2013. Calculated values of the indirect optical transitions were in the range of 2.96 ÷ 3.01 eV for samples annealed at 650 ÷ 700 ºC, for samples annealed at 550 ÷ 600 ºC they were in the range of 3.10÷3.15 eV and in the range of 3.2 ÷ 3.3 eV for samples, annealed at 450 ºC.…”

“…As seen, the films are similar in composition. Samples annealed at low temperature exhibit a higher content of C. In order to avoid the inclusion of C, some authors [Chow 2001] advised before scanning the samples to be cleaned with argon at 4 kV.…”

“…Films showed rather smooth and compact surface in both deposition methods. It was suggested that at the annealing temperature of 450 ºC anatase phase was formed, and at the temperatures above 600 ºCrutile phase [Fu 2006, Sreemany 2010, Huang 2011. Optical properties of TiO 2 were investigated by the spectral characteristics of transmittance measured with a spectrophotometer UV-VIS SPECTROMOM 195D within a range of wavelengths of 200 ÷ 900 nm.…”

“…Its light sensitivity can also be used for design of gas and humidity sensors, as well as other types of sensors. Due to the wide band gap of 3.0 eV and 3.3 eV of the TiO 2 crystalline phases rutile and anatase, respectively, this material is sensitive to the illumination in the wavelength range of 320÷400 nm, which renders the TiO 2 -based photodiodes suitable for UV sensors [Hossein-Babaei 2012, Kargan 2012, Tian 2015, Xie 2013.…”