不同尺寸纳米TiO<sub>2</sub>多孔薄膜中陷阱态分布研究
摘要
The number and distribution of trap states in nanoporous TiO<sub>2</sub> thin films effect on the electron transport and recombination, and then affect the dye-sensitized solar cell (DSSCs) performance. This paper study the trap state number in nanoporous films composed of 10, 20, 80 and 200 nm TiO<sub>2</sub> nanoparticles by means of three electrode system, based on the electrochemical impedance spectroscopy (EIS) and the cyclic voltammetry (CV). The results show that the content of trap states decreases with the increase of particle size. And X-ray photoelectron spectroscopy (XPS) characterization shows that the content of Ti<sup>3+</sup> and oxygen vacancies in the porous films decrease with the increase of particle size. The research provides a description of microscopic mechanism for the effect of porous films with different sizes on cell photovoltaic performances.