【摘要】 本文研究了表面修饰的TiO₂半导体超微粒子的光学性质,指出TiO₂半导体超微粒子表面与其表面修饰的有机分子之间的强化学健作用,明显地改变了半导体超微粒子的光学性质,在其带隙间形成了新的表面态能级（2.22eV）.更多还原

【Abstract】 The optical properties of TiO2 semiconductor ultrafine particles with surface modification was investigated, in contrast with those of bulk and naked TiO2 ultrafine particles. The experimental results show that the strong chemical interactions between the surface of the particles and the organic molecules has significantly changed their properties.The TiO2 ultrafine particles coated with a layer of organic molecules (stearic acid) were obtained through the following reaction.The size of the TiO2 ultrafine particles was determined to be 5nm and they are spherically-shaped.The absorption and photoluminescence spectra of TiO2 semiconductor ultrafine particles with surface modification were meassured at room temperature. We found that the TiO2 organosol became red after the particles had been coated with the organic molecules and the absorption spectrum red shifted relatively to the bulk material and the nakedparticles. Their photoluminescencc with the peak energy is 2.26eV. The corresponding wavelength is 548nm.According to the relation between the absorption cpefficien and band gapthe absorption band gap of the TiO2 ultrafine particles can be estimated at 2.22eV.In conclusion, the chemical interaction between the surface of the particles and the organic molecules significantly influences the optical properties of TiO2 semiconductor ultrafine particles, and a new surface state level in their band gap is formed.更多还原