Pulsed Laser Liquid Phase Deposition Of Tio <sub> 2 </ Sub> Thin Film And Its Optical Performance

Due to low cost, simple process, Dye-sensitized solar cells (DSSC) as a novel solar cell has attracted wide attention.nano-TiO 2 thin film whose morphological feature has a great influence in DSSC is the major component of DSSC.In this paper, a novel technique, the pulsed laser-induced liquid deposition (PLLD) method which comes from the traditional method (PLD), and the method of ordinary hydrolysis of TiO 2 have been employed to grow nanocrystalline TiO 2 films at room temperature. A variety of characterization techniques (TEM, SEM, XRD, etc.) were employed to characterize the morphology and properties of the film. And specific content and conclusions as follows:(1) Using TiCl 4 as the precursor, TiO 2 thin film which was obtained by hydrolysis method was three-dimensional hollow shape, no cracks and it was composed by rod-like with 40nm diameter rutile TiO 2 nanoparticles. Before and after being annealed in 450℃,the average size of TiO 2 nanoparticles were 4.3nm and 7.5nm respectively. Preferred orientation of TiO 2 film was along the (110) and (001) direction. The efficiency of dye-sensitized cells made by this kind of TiO 2 film was 1.31%.(2) Some 300nm size "nano-flower" was made of rutile TiO 2 nonporous film as crystal unit reunion which was deposited on the FTO substrate by PLLD. The "nano-flower" formation was discussed as follows: First, after laser irradiation, the substrate surface is "active" and plays a strong role in adsorption and orientation of TiO 2 nanoparticles. Secondly, in the laser irradiation process, TiO 2 nanoparticles have become"active"makes the cohesion between particles and particles be strong which result in the reunification process of standing on the surface of the substrate. Under the same laser radiation, irradiation time was too long to no film formation. And too short time cant result in forming TiO 2 "nano-flower" which helps to dye adsorbed(3) Optical absorption property of TiO 2 thin films obtained by PLLD were absorbed by N719 dye was help to improve the cells optoelectronic performance. The band gap TiO 2 thin film obtained by PLLD was 3.01eV because of its peculiar morphology.(4) The conversion efficiency of dye-sensitized solar cells (DSSC) which were assembled by nano-TiO 2 films obtained by PLLD is 2.31% higher than the hydrolysis method; TiO 2 film with 1um thickness obtained by the PLLD will help to the dye adsorption, contribute to photo-carrier transport, and result in relatively high photoelectric conversion efficiency.