Thin solid films of organic conjugated mole-cules are at the center of organic electronics. Low solubility and high sublimation temperature of porphyrin-perylene arrays make it impossible to fabricate uniform solid films with spin-coating and vacuum deposition methodology, though these arrays have important applications in the area of opto-electronics. Here we show that high quality thin films of a porphyrin-perylene array can be prepared by electro-chemical deposition, a facile and widely used film-forming technique. The electrophoretic species are protonated por-phyrin-perylene molecules, which allow us to grow molecular array films on electrodes. By annealing in ammonia atmos-phere or in vacuum at elevated temperature, the protons coordinated with molecular arrays on the deposited films can be eliminated and the porphyrin-perylene arrays recovered to their pristine state.
We present an efficient synthetic route towards two kinds of perylene-porphyrin arrays. Starting from 5, 10, 15, 20-meso-tetraphenylporphyrin, two novel 9a and 9b were designed and synthesized with 40.3% and 35.1% yield, respectively.
TiO 2 nanoribbons were synthesized hydrothermally via the reaction of TiO 2 particles and NaOH solution. Their photovoltaic properties were studied by surface photovoltage spectroscopy (SPS) and electric field-induced surface photovoltage spectroscopy (FISPS). Under the external field, new photovoltaic response bands were found from 375 nm to 550 nm. It is suggested that these response bands resulted from the surface states, which can be ascribed to the formation of steps and kinks in the TiO 2 nanoribbons.
