Nc-si: (al <sub> 2 </ Sub> O <sub> 3 </ Sub> + Of Sio <sub> 2 </ Sub>) Composite Films And Sns Films And Their Features

This thesis is composited of two parts. In the first part, nc-Si:(Al2O3+SiO2) composite film has been prepared by thermal evaporation and annealing in air. Structural and optical properties of the composite film were studied using X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Raman scattering spectrograph, Transmission Electron Microscopy (TEM), and fluorescence spectrophotometer. We studied thermoelectric property of the film by a thermoelectric testing instrument which was devised by ourselves. In the second part, SnS thin film was deposited by thermal evaporation on glass substrate and annealed in N2, using SnS powder as evaporation source. The structural and optical properties of the film were studied by XRD, Atom Force Microscopy (AFM), SEM, Energy Dispersive Spectroscope (EDS), UV-VIS-NIR spectroscopy, and Room temperature photoluminescence spectrum. The study results were obtained as follows:1. The XRD measurements result indicated that after annealing A1 had been oxidized totally and there appeared nc-Si in nc-Si:(Al2O3+SiO2) composite film. The average size of the nc-Si is about 25nm, which was estimated using the Scherrer formula. The lattice constant of the nc-Si determined from the central peak, position of Si peak is 0.316nm.2. Crystallization rate of the Si is 96% in the composited film, which demonstrated that the most of Si in the film was crystallized.3. It is found that the thickness of the annealed film is thicker than that of the as-deposited film. This reflects that A1 diffused downward into substrate during the annealing process.4. With the photons excitation at 325 nm, nc-Si:(Al2O3+SiO2) composite film gave out light (480nm～780nm), which come from defects and nc-Si.5. The composite film shows n-type conductivity and the Seebeck coefficient and electrical resistivity of the composite film decrease with increasing temperature from room temperature (293 K) to 413 K. The Seebeck coefficient of the nc-Si:(Al2O3+SiO2) composite film is-642μV/K. at 293 K,-225μV/K at 413 K, and the thermoelectric power factor was calculated to be 7.26×10-5 Wm-1K-2 at 293K.6. The as-deposited SnS thin film is crystalline and an improvement in the crystallinity is observed at 200℃. The grain size of SnS is 15.4nm, it had no obvious change at different annealing temperature.7. There are some Sn2S3 in the prepared SnS films when the annealing temperature is above 400 ℃.8. With the annealing temperature increasing, the Rms roughness values of the SnS thin films increase.9. Before and after annealing, the optical band-gap energy of the SnS thin film is almost same. The optical band-gap energy of the SnS thin film annealed at 200℃is 1.39 eV.10. With photon excitation at 325 nm, the emission peaks of SnS thin films prepared at different conditions locate at 498 nm and 530 nm, which come from defects in SnS films.