用ECRCVD法制备的纳米碳化硅薄膜及其室温下的强光发射

用电子回旋共振化学气相沉积(ECRCVD)方法制备了纳米碳化硅薄膜.实验中发现:在高氢稀释反应气体和高微波功率条件下,可以得到结构上具有纳米碳化硅晶粒镶嵌在碳化硅无序网络中的薄膜.用高分辩透射电子显微镜、傅里叶红外吸收谱、Raman散射和X射线光电子谱等分析手段对薄膜的结构进行了分析.在室温条件下,薄膜能够发出强烈的短波长可见光,发光峰位于能量为2.64eV处.瞬态光谱研究表明样品的光致发光寿命为纳秒数量级,表现出直接跃迁复合的特征.这种材料有希望在大面积平面显示器件中得到应用.

Nanocrystalline Silicon Carbide Films Deposited by ECR Chemical Vapour Deposition and Its Photoluminescence

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.