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为了得到光电化学性质稳定且具有宽的光吸收范围的光电极材料, 给出了一种禁带宽度梯度化的氧化物半导体薄膜电极的设计. 用溶胶凝胶法将不同V/Ti比的溶胶逐层涂于基板上, 通过热处理得到了禁带宽度梯度化的Ti1-xVxO2薄膜电极. XPS结果显示所得薄膜中形成了组成梯度. 这种Ti1-xVxO2薄膜电极的光电化学性质稳定, 光生伏打约为360 mV, 可见光区具有明显的光电流. 与纯的TiO2薄膜电极相比, Ti1-xVxO2薄膜电极的光电流起始电压正移了. 这是由于电极表面富集的钒形成了电子空穴复合中心. Ti1-xVxO2的导带最低能级比TiO2的低可能是引起正移的另一原因. 阻抗分析表明Ti1-xVxO2的受主密度比TiO2的高.
In order to obtain a photoelectrode material with stable photoelectrochemical properties and a wide range of light absorption, a design of a forbidden band width gradient oxide semiconductor thin film electrode is proposed. Sol-gel method with different V / Ti ratio sol The Ti1-xVxO2 thin film electrode with gradient forbidden band width was obtained by heat treatment.The XPS results showed that the compositional gradient was formed in the obtained thin film.The photoelectrochemical properties of the Ti1-xVxO2 thin film electrode were stable, About 360 mV, visible light region has a significant photocurrent .Compared with the pure TiO2 thin film electrode, Ti1-xVxO2 thin film electrode positive current photocurrent positive shift.This is due to the electrode surface enriched in vanadium to form an electron empty Hole recombination center. Another reason why the lowest conduction band of Ti1-xVxO2 is lower than that of TiO2 is another reason for the positive shift. The impedance analysis shows that the acceptor density of Ti1-xVxO2 is higher than that of TiO2.