scholarly journals Thickness-Dependent Swelling Behavior of Vapor-Deposited Hydrogel Thin Films

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 757 ◽  
Author(s):  
Fabian Muralter ◽  
Alberto Perrotta ◽  
Anna Maria Coclite
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Chemical Vapor ◽  
Solution Temperature ◽  
Cross Linking ◽  
Temperature Sensitive ◽  
Critical Solution Temperature ◽  
Precise Control ◽  
Initiated Chemical Vapor Deposition ◽  
Deposited Film

Hydrogel thin films containing temperature sensitive chemical functionalities (such as N-isopropylacrylamide, NIPAAm) are particularly interesting for sensor and actuator setups. Complex 3D structures can be conformally coated by the solvent free technique initiated Chemical Vapor Deposition, with precise control over chemical composition and film thickness. In this study, NIPAAm-based thin films with film thicknesses ranging from tens to several hundreds of nanometers and with different amounts of cross-linking were deposited. Above the lower critical solution temperature (LCST), these films repel out water and hence shrink. The amount of cross-linking and the deposited film thickness were successfully identified to both affect shape and position of the LCST transition of these systems: a promising basis for tuning response properties.

scholarly journals Optical Constant and Conformality Analysis of SiO2 Thin Films Deposited on Linear Array Microstructure Substrate by PECVD

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 510
Author(s):  
Yongqiang Pan ◽  
Huan Liu ◽  
Zhuoman Wang ◽  
Jinmei Jia ◽  
Jijie Zhao
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Deposition Rate ◽  
Optical Constant ◽  
Photoelectron Spectroscopy ◽  
Linear Array ◽  
Chemical Vapor ◽  
Rf Plasma ◽  
X Ray ◽  
Sio2 Thin Film

SiO2 thin films are deposited by radio frequency (RF) plasma-enhanced chemical vapor deposition (PECVD) technique using SiH4 and N2O as precursor gases. The stoichiometry of SiO2 thin films is determined by the X-ray photoelectron spectroscopy (XPS), and the optical constant n and k are obtained by using variable angle spectroscopic ellipsometer (VASE) in the spectral range 380–1600 nm. The refractive index and extinction coefficient of the deposited SiO2 thin films at 500 nm are 1.464 and 0.0069, respectively. The deposition rate of SiO2 thin films is controlled by changing the reaction pressure. The effects of deposition rate, film thickness, and microstructure size on the conformality of SiO2 thin films are studied. The conformality of SiO2 thin films increases from 0.68 to 0.91, with the increase of deposition rate of the SiO2 thin film from 20.84 to 41.92 nm/min. The conformality of SiO2 thin films decreases with the increase of film thickness, and the higher the step height, the smaller the conformality of SiO2 thin films.

scholarly journals Precise control of Jeff=12 magnetic properties in Sr2IrO4 epitaxial thin films by variation of strain and thin film thickness

2020 ◽  
Vol 102 (21) ◽  
Author(s):  
Stephan Geprägs ◽  
Björn Erik Skovdal ◽  
Monika Scheufele ◽  
Matthias Opel ◽  
Didier Wermeille ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Magnetic Properties ◽  
Film Thickness ◽  
Epitaxial Thin Films ◽  
Thin Film Thickness ◽  
Precise Control

Bio-inspired Passive Skin Cooling for Handheld Microelectronics Devices

2012 ◽  
Vol 134 (1) ◽  
Author(s):  
Zhi Huang ◽  
Xinsheng Zhang ◽  
Ming Zhou ◽  
Xiaoding Xu ◽  
Xianzheng Zhang ◽  
...  
Keyword(s):  
Heat Dissipation ◽  
Handheld Devices ◽  
Solution Temperature ◽  
Passive Cooling ◽  
Temperature Sensitive ◽  
Operation System ◽  
Critical Solution Temperature ◽  
Handheld Device ◽  
Skin Cooling ◽  
Cooling Technology

Increasing functionality demands more heat dissipation from the skin of handheld devices. The maximum amount of heat that can be dissipated passively, prescribed by the natural convection and blackbody radiation theories, is becoming the bottleneck. In this letter, we propose a novel bio-inspirited technique that may overcome this passive cooling limit. It is made possible by using a biomimetic skin capable of perspiration on demand. The key component of the biomimetic skin is a thin layer of temperature sensitive hydro gel (TSHG). The TSHG layer can sweat the skin with moisture when the skin temperature is higher than the TSHG’s lower critical solution temperature (LCST), and thus boost the heat dissipation rate through evaporation. The TSHG layer can absorb moisture at low temperature to replenish. With this novel passive cooling technology, a handheld device can have nearly four times more power beyond the traditional passive cooling limit, and may be powerful enough to run a desktop operation system like a full functional personal computer.

Optimization of p-type Nanocrystalline Silicon Thin Films for Solar Cells and Photodiodes

2009 ◽  
Vol 1153 ◽  
Author(s):  
Yuri Vygranenko ◽  
Ehsanollah Fathi ◽  
Andrei Sazonov ◽  
Manuela Vieira ◽  
Gregory Heiler ◽  
...  
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Chemical Vapor ◽  
Percolation Cluster ◽  
Nanocrystalline Silicon ◽  
Film Structure ◽  
Silicon Thin Films ◽  
Low Leakage ◽  
In Doping ◽  
P Type

AbstractWe report on structural, electronic, and optical properties of boron-doped, hydrogenated nanocrystalline silicon (nc-Si:H) thin films deposited by plasma-enhanced chemical vapor deposition (PECVD) at a substrate temperature of 150°C. Film properties were studied as a function of trimethylboron-to-silane ratio and film thickness. The film thickness was varied in the range from 14 to 100 nm. The conductivity of 60 nm thick films reached a peak value of 0.07 S/cm at a doping ratio of 1%. As a result of amorphization of the film structure, which was indicated by Raman spectra measurements, any further increase in doping reduced conductivity. We also observed an abrupt increase in conductivity with increasing film thickness ascribed to a percolation cluster composed of silicon nanocrystallites. The absorption loss of 25% at a wavelength of 400 nm was measured for the films with optimized conductivity deposited on glass and glass/ZnO:Al substrates. A low-leakage, blue-enhanced p-i-n photodiode with an nc-Si p-layer was also fabricated and characterized.

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