Evaporated Films and Ultra-high Vacuum

Titanium monoxide ultra-thin coatings evaporated onto polycrystalline copper films

We evaporated polycrystalline copper thin films of thickness between 10 and 100nm on silicon substrates with their native oxide under ultra-high-vacuum conditions. Some of them were exposed to air for a period ranging from 1 day to 2 weeks. X-ray photoelectron spectroscopy (XPS) revealed a clean copper surface with a trace of oxygen. These films that were exposed to air presented oxides in the ...

Tunable Photoluminescence via Thermally Evaporated ZnS Ultra Thin Films

ZnS thin films have been deposited by thermal evaporation at various deposition rates. By controlling the deposition rate, the position of the maximum in the photoluminescence spectra could be easily tuned from 2.9 to 2.0 eV, which produced a corresponding change in the emission color. The optical and morphological characteristics of the ZnS thin films were measured. The photoluminescence spect...

Vacuum fluctuation forces between ultra-thin films

We have investigated the role of the quantum size effects in the evaluation of the force caused by electromagnetic vacuum fluctuations between ultra-thin films, using the dielectric tensor derived from the particle in a box model. Comparison with the results obtained by adopting a continuum dielectric model shows that, for film thicknesses of 1÷10 nm, the electron confinement causes changes in ...

Study of Wavelength Dependence of Optical Constants for Znse Vacuum Evaporated Thin Films

Vacuum evaporated crystalline films of Zinc Selenide (ZnSe) have been characterized by using optical spectroscopy (especially transmission and absorption spectra). Thin films of ZnSe have been deposited by vacuum evaporation technique on highly clean glass substrates and their optical properties such as refractive index (n), extinction coefficient (k), and energy band gap have been studied. The...

Rolling Contact Fatigue in Ultra High Vacuum