Boron-doped <i>a</i>-Si:H thin films were prepared by plasma-enhanced chemical vapor deposition technique. As-deposited samples were thermally annealed at different temperatures from 450 °C to 1000 °C. The microstructures and electrical properties have been evaluated for the amorphous and nano-crystalline structures. It was found that thermal annealing can efficiently activate the dopant in films accompanying with formation of nc-Si grains. During the transition process from amorphous to nano-crystalline structures, the room temperature dark conductivity is increased from 6.6×10<sup>-4</sup> S cm<sup>-1</sup> to 2.8×10<sup>2</sup> S cm<sup>-1</sup>. Based on the properties of p-type silicon films, the P-N junction solar cells were prepared on n-type nc-Si substrate. It was shown that the conversion efficiency is increased monotonously as increasing the annealing temperature. Form the results, it can be implied that the solar cells with higher conversion efficiency can be obtained by using the method of thermal annealing.
A series of amorphous-Si/silicon oxynitride multilayer were deposited on the ITO (40Ω/cm) glass substrates in a very high frequency plasma enhanced chemical vapor deposition (VHF-PECVD) system. We prepared 8-period a-Si/ SiO<sub>x</sub>N<sub>y</sub> multilayer with thickness of 4 nm both for the amorphous Si and SiO<sub>x</sub>N<sub>y </sub>sublayers. The EL diodes can operate at room temperature and the turn-on voltage is about 10V. We study the room-temperature electroluminescence from as deposited amorphous-Si/silicon oxynitride multilayer structure.
The Eu-doped SiOC films were prepared by magnetron sputtering technique at a low temperature of 250°C. The effects of the Eu<sub>2</sub>O<sub>3</sub> deposited power and post-thermal annealing temperature on the PL characteristics of the Eu-doped SiOC films were investigated. It is found that the photoluminescence intensity could be enhanced by more than tenfold by increasing the Eu<sub>2</sub>O<sub>3</sub> deposited power from 20W to 80W. Furthermore, very bright blue light emission can be clearly observed with the naked eye in a bright room for the Eu-doped SiOC films prepared at a Eu<sub>2</sub>O<sub>3</sub> deposited power of 80 W. The improved PL intensity is attributed to the increasing number density of europium silicate clusters as a result of the increasing Eu<sub>2</sub>O<sub>3</sub> deposited power as well as high annealing temperatures.