Study On Preparation Of Si-rich Silicon Nitride And Silicon Quantum Dot Solar Cell Materials By Hot Wire

Silicon rich silicon nitride thin film materials and contains silicon quantum dots of silicon rich silicon nitride film for application to optoelectronic devices and third generation silicon quantum dot thin film solar cells, in optoelectronic devices can effectively improve the luminous efficiency, in solar cells can improve the utilization rate of photon, thereby improving battery photoelectric conversion efficiency. Based on these advantages,Silicon-rich silicon nitride thin films were deposited by hot wire chemical vapor deposition method The structure, band gap width, light-emitting performance and surface morphology of thin films were characterized and analyzed by Fourier transform infrared absorption spectroscopy, ultraviolet-visible spectra, photoluminescence spectra and SEM etc, respectively. The effects of nitrogen flow rate, gas flow rate and flow rate of the electric heating wire of thin film materials characterization discussion. The results showed that:1.The nitrogen content in the films decreases, silicon cluster grain buried in silicon nitride matrix grow up, Si-N bond density gradually decreases, optical band gap width Eg and the band tail energy Eu tend to decrease, atomic order degree in the films increase, with increase of nitrogen flow rates. And photoluminescence peak cited by nitrogen dangling bond defect states enhance. When nitrogen flow rate is 30sccm, Si-N bond of asymmetric stretching mode and Si-H bond of stretching vibration mode show a blue shift. When [N2]/[NH3] ratio is less than 5:1, influence of nitrogen flow rate on nitrogen content in films is more obvious. Therefore, properly reducing nitrogen flow rate helps to prepare a rich silicon nitride thin film materials.2. silicon rich silicon nitride films were prepared by changing the silane flow with other parameters keep constant. With the increase of the silane flow rate, the increased nitrogen atoms in the film makes the band gap broaden. The silane flow rate will not only influence nitrogen atoms dope into the films, but also affect the size of silicon cluster embedded in the matrix By adjusting the silane flow rate to control silicon particle size in the silicon nitride thin film matrix to prepare the eligible silicon quantum particles.3.The hot filament temperatures is an important parameter which influence the film properties, by adjusting the hot filament temperatures to prepare silicon rich silicon nitride films. The decomposition rate of silane and ammonia can be influenced by the hot filament temperatures, which leads to the difference of the bonding density in the films, which results in the difference of the silicon clusters in the silicon nitride matrix.4. The small diameter silicon cluster can be achieved by appropriately decreasing the silane concentration and the hot filament temperatures.