Structure And Luminescent Properties Of The Doped Amorphous Silicon-based Films

To improve the luminescence efficiency and the intensity of luminescence, attempts doping with C and N elements into the silicon-based films .A series of composite thin films of Si-Si02 , SiOx:C and SiOxNy were prepared by dual ion beam co-sputtering method. The microstructures of films were characterized by means of TEM, XRD, FTIR, XPS and studied the luminescent properties of them by aid of the PL. Testing of TEM and XRD indicate that films are amorphous and father analysis from FTIR and XPS showed that the impurities(C and N ) are free states in the film at room temperature.The possible mechanism of light emission have been discussed, under ultraviolet excitation (240nm), all the sample emit the same luminescent peak at 470nm which imply that the peak is foreign to doping. The 470nm peak is usually originated from the neutral oxygen vacancy (03=Si-Si=03). After doping with C and N there are different luminescent peaks among the films of Si-Si02 , SiOx:C and SiOxNy . The peak at 378nm from Si-Si02 film is related to the silicon nano-clusters in the films and the peak at 420nm from SiOx:C and at 400nm from SiO,Ny are probably derived from the new luminescent centers(LCs) which consist of Si,0 and the impurities(C or N).