Pulsed Laser Deposition Of Silicon-based Light-emitting Film And Its Characteristics

Si-rich SiO2 films and Si/SiO2 multilayer films were fabricated by pulsed laser deposition. The surface appearance and microstructure of the films were characterized by Atomic Force microscope(AFM),X-ray diffraction (XRD)and Raman Scattering spectroscopy (Raman).The effects of several experimental parameters, such as gas pressure, atmosphere and anneal temperature on the luminescence properties of the films were studied. The mechanism of PL property of the Si-base films was discussed.The testing of PL spectra showed that ultraviolet and visible emission can be observed in the samples, in which the emission from ultraviolet to purple has the strongest intensity and blue emission intensity is weaker, the red emission intensity is the weakest.The emission spectra of Si-rich SiO2 films have emission peaks at 350nm, 460nm, 650nm and 666nm when excitated by 270nm ultraviolet. When the films were excitated by 290nm ultraviolet, the sample emission peaks at 435nm, 450nm,467nm, 490nm and 685nm can be observed. The emission peaks of Si/SiO2 multilayer films were located at 323nm, 346nm, 403nm, 450nm-470nm, 490nm, 650nm, 666nm and 690nm when excitated by 270nm and 290nm ultraviolet.From the analysis of the experiment results we thought The red emission located at 680nm was derived from the Quantum Confinement Effect of Si nanometer grains and the non-bridge oxygen vacancy defects of silica and the red emissin located at 650nm was derived from the Quantum Confinement Effect of Si nanometer grains and the oxygen vacancy defects of silica The blue emission is related to the oxygen vacancy defects of silica. UV and purple emission were derived from the combination of oxygen vacancy defects of silica and the interface luminescence of the Si nanometer grains and silica.The red emission of Si-base films is related to the density of the nanometer grains and the number of the grains in the bohr radius. The preparation technic has great effect on the UV to red emission of the films. Emission of Si in certain wave band can be obtained by utilizing and controlling the doped oxygen effectively.