Papers by Keyword: Silicon Doping

Abstract: Effect of storage in air on silicon doped indium oxide (In-Si-O) thin-film transistors fabricated via solution processing has been investigated. The on/off ratio drastically increased from 10¹ just after fabrication to 10⁵ on the 10-day storage, whereas the mobility slightly decreased from 1.4 cm²/Vs to 0.38 cm²/Vs. Time constant of aging effect was 3.6 days. The behavior suggests that oxygen defects in In-Si-O films, which may be produced during thermal evaporation of Al electrodes under high vacuum, are eliminated.

Abstract: Si-doped diamond films are deposited on cobalt cemented tungsten carbide (WC-Co) welding dies using hot filament chemical vapor deposition (HFCVD) method, where tetraethoxysilane (C8H20O4Si) is introduced in the reactive chamber as silicon source by bubbling method. Filed emission scanning electron microscope (FESEM) and Raman spectroscopy are used to characterize the as-deposited diamond films. The results show that silicon doping can reduce the diamond crystal size and residual stress of diamond films, and also increase the FWHM of first order diamond Raman line. The polishing time of diamond coated welding dies also can be shortened by silicon doping. Si-doped diamond coated welding dies possesses comparable practical application performance with conventional diamond coated welding dies. Compared with the nylon and WC-Co welding dies, the working lifetime of diamond coated welding dies increases 200 and 10 times, respectively.

Abstract: We present an analysis of charge effects on the highly silicon doped heterofullerenes C30Si30. Structural and electronic properties are investigated by the inclusion of an extra pos- itive and negative charge in the neutral system. The calculations are performed based on the framework of Car-Parrinello molecular dynamics within the spin density version of density functional theory. Structural properties are not significantly affected by adding to or extracting from the C30Si30 heterofullerene one electron. However, the change of charge states has some ef- fects on the electronic properties of heterofullerenes. In the negatively charged system, negative charges are found in the inner part of the Si region, thereby suggesting potential applications of Si-based heterofullerenes as anionic systems.