Novel linear and star branched triphenylamine-containing aromatic imides were designed and synthesized by the condensation between amine-substituted triphenylamine and naphthalene-1, 4, 5, 8-tetra-carboxylic dianhydride in order to investigate the influence of topological structure on the photophysical performance. The polyimides were characterized by elementary analysis and FTIR measurements. Thermogravimetric analysis (TGA) shows that the onset temperatures of decomposition (Td) for 5% mass loss range from 371 to 445 ℃. UV-Vis spectrum, quantum chemical calculation and cyclic voltammetry (CV) were used to obtain the dependence of energy levels on the function of structures. The introduction of triphenylamine group changes the energy level of the entire dye system. The dye-sensitized solar cells (DSSCs) prepared by using the dyes have a strong photoelectric current response in visible light region of 400-600 nm.
Si nanoparticles are synthesized at a high rate(400-500 mg/h) using the perpendicular pulsed laser ablation(PPLA) on the silicon target at room temperature in Ar atmosphere.The PPLA method can also be used to obtain Si nanocrystal films with large areas on the glass substrate.These particles are etched with a mixture of hydrofluoric acid(HF) and nitric acid(HNO3) to reduce their sizes and the surfaces of these particles are passivated by the high-pressure water vapor annealing(HWA).After treating the particles exhibit blue emission(with maximum photoluminescence(PL) intensity at 404 nm) at room temperature.
