SYNTHESIS AND CHARACTERIZATION OF NANOCRYSTALLINE SILICON BY ATMOSPHERICS PRESSURE PLASMA JET -ELECTRONIC AND OPTICAL PROPERTIES-

点击翻译按钮获取中文摘要

Luminescent nanocrystalline silicon dots were fabricated on thermally grown SiO_2 at 120℃ by rf plasma-enhanced chemical vapor deposition using tetrachlorosilane, SiCl_4 and H_2. As-deposited Si dots exhibits photoluminescence (PL) in the visible region, consisting of two broad bands corresponding to photon energies of 1.38 and 1.48 eV. Storage in air enhances PL and shifts the PL peak energy to higher wavelengths for dots of diameter less than 10 nm. Fourier transform attenuated total reflection absorption spectroscopy (FTIR-ATR) study reveals that the spontaneous oxidation proceeds until saturation after 70 h at dot sizes of 3-5 nm. The relationship between PL intensity, blueshift of the PL peak energy, and surface termination species during oxidation indicates that these changes are attributed yo the increased density of radaitive centers at the Si nanocrystal dot/SiO_2 interface and enhancement of quantum confinement effect. In addition, we have developed the rf microplasma jet at atmospheric pressure. We also attempted the quick recrystallization of amorphous silicon using an plasma jet of argon. The recrystallized region also exhibits the strong visible PL.