scholarly journals Effect of Substrate and Thickness on the Photoconductivity of Nanoparticle Titanium Dioxide Thin Film Vacuum Ultraviolet Photoconductive Detector

Nanomaterials ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 10
Author(s):  
Marilou Cadatal-Raduban ◽  
Tomoki Kato ◽  
Yusuke Horiuchi ◽  
Jiří Olejníček ◽  
Michal Kohout ◽  
...  

Vacuum ultraviolet radiation (VUV, from 100 nm to 200 nm wavelength) is indispensable in many applications, but its detection is still challenging. We report the development of a VUV photoconductive detector, based on titanium dioxide (TiO2) nanoparticle thin films. The effect of crystallinity, optical quality, and crystallite size due to film thickness (80 nm, 500 nm, 1000 nm) and type of substrate (silicon Si, quartz SiO2, soda lime glass SLG) was investigated to explore ways of enhancing the photoconductivity of the detector. The TiO2 film deposited on SiO2 substrate with a film thickness of 80 nm exhibited the best photoconductivity, with a photocurrent of 5.35 milli-Amperes and a photosensitivity of 99.99% for a bias voltage of 70 V. The wavelength response of the detector can be adjusted by changing the thickness of the film as the cut-off shifts to a longer wavelength, as the film becomes thicker. The response time of the TiO2 detector is about 5.8 μs and is comparable to the 5.4 μs response time of a diamond UV sensor. The development of the TiO2 nanoparticle thin film detector is expected to contribute to the enhancement of the use of VUV radiation in an increasing number of important technological and scientific applications.

2013 ◽  
Vol 534 ◽  
pp. 12-14 ◽  
Author(s):  
Tatsuya Ishimaru ◽  
Mirai Ieda ◽  
Shingo Ono ◽  
Yuui Yokota ◽  
Takayuki Yanagida ◽  
...  

Volume 1 ◽  
2004 ◽  
Author(s):  
Yi Jia ◽  
Juan Guillermo Araya ◽  
Gustavo Gutie´rrez

Thin film temperature sensors integrated onto mechanical component surface are promising for real-time machine condition monitoring. In this paper one-dimensional heat conduction model has been developed to study the response time of the thin film sensors designed for monitoring of temperature distribution in elastohydrodynamic lubrication contact. A control volume approach was used to numerically analyze the effects of film thickness (from 0.1 μm to 100 μm), sensing materials, and substrate materials on the transient time response of the thin film sensor. Validation of the numerical model was compared to an analytical solution in a semi infinite domain. The time constants are obtained based on a constant heat load and sensor sensibility is studied when a typical dynamic pressure in lubricated contact is applied. The faster response time and the short time delay for a thin film sensor are expected in lower conductivity of substrate. It is also clear that the response time decreases with increasing film thickness and the conductivity of the substrate. Results show that when thickness of the sensor is less than 1 μm, the sensor is feasible to capture the transient temperature profile in real-time for machine health monitoring under various operating condition.


Author(s):  
Mirai Ieda ◽  
Tatsuya Ishimaru ◽  
Shingo Ono ◽  
Yuui Yokota ◽  
Takayuki Yanagida ◽  
...  

Carbon ◽  
2021 ◽  
Vol 178 ◽  
pp. 506-514
Author(s):  
Meiyu He ◽  
Jiayue Han ◽  
Xingwei Han ◽  
Jun Gou ◽  
Ming Yang ◽  
...  

Coatings ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 23
Author(s):  
Weiguang Zhang ◽  
Jijun Li ◽  
Yongming Xing ◽  
Xiaomeng Nie ◽  
Fengchao Lang ◽  
...  

SiO2 thin films are widely used in micro-electro-mechanical systems, integrated circuits and optical thin film devices. Tremendous efforts have been devoted to studying the preparation technology and optical properties of SiO2 thin films, but little attention has been paid to their mechanical properties. Herein, the surface morphology of the 500-nm-thick, 1000-nm-thick and 2000-nm-thick SiO2 thin films on the Si substrates was observed by atomic force microscopy. The hardnesses of the three SiO2 thin films with different thicknesses were investigated by nanoindentation technique, and the dependence of the hardness of the SiO2 thin film with its thickness was analyzed. The results showed that the average grain size of SiO2 thin film increased with increasing film thickness. For the three SiO2 thin films with different thicknesses, the same relative penetration depth range of ~0.4–0.5 existed, above which the intrinsic hardness without substrate influence can be determined. The average intrinsic hardness of the SiO2 thin film decreased with the increasing film thickness and average grain size, which showed the similar trend with the Hall-Petch type relationship.


2020 ◽  
Vol 102 (21) ◽  
Author(s):  
Stephan Geprägs ◽  
Björn Erik Skovdal ◽  
Monika Scheufele ◽  
Matthias Opel ◽  
Didier Wermeille ◽  
...  

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4056
Author(s):  
José Javier Imas ◽  
Carlos R. Zamarreño ◽  
Ignacio del Villar ◽  
Ignacio R. Matías

A fiber Bragg grating patterned on a SnO2 thin film deposited on the flat surface of a D-shaped polished optical fiber is studied in this work. The fabrication parameters of this structure were optimized to achieve a trade-off among reflected power, full width half maximum (FWHM), sensitivity to the surrounding refractive index (SRI), and figure of merit (FOM). In the first place, the influence of the thin film thickness, the cladding thickness between the core and the flat surface of the D-shaped fiber (neck), and the length of the D-shaped zone over the reflected power and the FWHM were assessed. Reflected peak powers in the range from −2 dB to −10 dB can be easily achieved with FWHM below 100 pm. In the second place, the sensitivity to the SRI, the FWHM, and the FOM were analyzed for variations of the SRI in the 1.33–1.4 range, the neck, and the thin-film thickness. The best sensitivities theoretically achieved for this device are next to 40 nm/RIU, while the best FOM has a value of 114 RIU−1.


2019 ◽  
Vol 682 ◽  
pp. 109-120 ◽  
Author(s):  
Wjatscheslaw Sakiew ◽  
Stefan Schrameyer ◽  
Marco Jupé ◽  
Philippe Schwerdtner ◽  
Nick Erhart ◽  
...  

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