Nanocrystalline Silicon Carbide Films Deposited by ECR Chemical Vapour Deposition and Its Photoluminescence
用ECRCVD法制备的纳米碳化硅薄膜及其室温下的强光发射

Nanocrystalline silicon carbide (nc SiC) films are fabricated by the electron cyclotron resonance chemical vapour deposition (ECRCVD) technique.It is found experimently that under the deposition conditions of reaction gas with strong hydrogen dilution and of high microwave power,various films containing SiC nanocrystallites embedded in a SiC amorphous matrix could be obtained.By using high resolution transmission electron microscopy,infrared absorption,Raman scattering and X ray photoelectron spectroscopy various structures of thin films are analyzed.Very strong photoluminescence in the visible range with a peak energy of 2 64eV could be observed from these films at room temperature.Temporal evolution of the PL at the peak emission energy exhibits a bi exponential decay process with lifetimes of picoseconds and nanoseconds.The strong light emission with short PL lifetimes suggest that the radiative recombination is a result of direct optical transitions in the SiC nanocrystallites.