摘要
溶胶-凝胶法制备了添加聚乙二醇和Al3+的TiO2薄膜,研究了薄膜的半导体特性和气敏性.添加聚乙二醇使TiO2薄膜的荧光发射峰从未添加的650 nm蓝移至600 nm处.添加聚乙二醇(相对分子质量2000)2.0 g/100mL的TiO2薄膜在还原性气氛中电阻值增大,在350℃下薄膜对1.0×10-3(体积分数)CO的灵敏度约为3.4;进而掺杂离子半径较小的Al3+,能够提高薄膜对CO的气敏性:在350℃时添加聚乙二醇且Al3+摩尔分数为50/0、100/0的薄膜对1.0×10-3(体积分数)CO的灵敏度分别为5.0和20.4.X射线光电子能谱表征说明,由于Al3+的晶格替代和氧间隙原子使添加有聚乙二醇和Al3+的TiO2薄膜产生以空穴为主的传导机制,表现出P型半导体特性.该研究结果对于研发TiO基的气敏传感器、新型太阳能电池具有重要意义.
TiO2 films were prepared with the dopant of polyethylene glycol（PEG） and Al^3＋ through the Sol-Gel method, then the semiconductor and gas-sensing property of the synthesized TiO2 films were investigated. It was indicated that the addition of PEG made the luminescence spectra peaks of TiO2 films blue-shift from 650 nm to 600 nm. Resistance of the 2.0 g/100 mL PEG2 000-doped TiO2 films increased under the reducing atmosphere, and the films had a maximum gas sensitivity of 3.4 to 1.0 ×10^-3（volume fraction）CO at 350 ℃. Consequent addition of Al^3＋ to the TiO2 films enhanced the gas sensitivity further. For the TiO2 films with the dop- ant of 2.0 g/100 mL PEG2 000 and 5% or 10% Al^3＋ , the maximum gas sensitivity to 1.0 × 10^-3 （ volume fraction） CO was 5.0 and 20.4, respectively. X-ray photoelectron spectroscopy characterization indicated that both the crystal lattice displacement of Al^3＋ and the excess oxygen atom resulted in the cavity conducting mechanism of the TiO2 films with the dopant of PEG and Al^3＋ , which is the typical property of P-type semiconductors. These results were important to develop TiO2-based gas sensors and solar cells.
出处
《天津大学学报》
EI
CAS
CSCD
北大核心
2007年第8期887-891,共5页
Journal of Tianjin University(Science and Technology)
基金
天津市科委科技攻关计划重大资助项目(05YFGDGX10000)
