聚苯胺基固态染料敏化太阳电池中电子输运性能的研究

以导电聚苯胺为空穴传输材料，制备了固态染料敏化太阳电池(DSC).利用强度调制光电流谱(IMPS)和强度调制光电压谱(IMVS)研究了TiO₂多孔膜内的电子输运及复合过程.通过TiO₂多孔膜内电子的平均传输时间(τ_d)和电子寿命(τ_n)及对IMPS实验数据的拟合，获得电子在TiO₂膜内的有效扩散系数(D_n)和扩散长度(L_n).这些聚苯胺基电池中的τ_n值为相应的液体型电池的1/10倍左右，表明在该固体电池中存在严重的光生电子的复合过程，这很可能主要是与氧化态染料分子和导电电子间的复合有关.随着TiO₂膜厚的增加，τ_n和τ_d均变小，但D_n和L_n随之增加，只有在合适的膜厚范围内才能获得较高的光伏性能. 关键词： 聚苯胺 染料敏化太阳电池 IMPS IMVS

Electron transport in solid-state dye-sensitized solar cells based on polyaniline

Solid-state dye-sensitized solar cells (DSCs) were prepared using polaniline (PANI) as hole- transport material. The charge transport and recombination in the cells were studied by means of intensity modulated photocurrent spectroscopy (IMPS) and intensity modulated photovoltage spectroscopy (IMVS). On the basis of lifetime (τ_n) and mean transit time (τ_d) of the electrons in nanoporous TiO₂ film and fitting of the IMPS response, the effective diffusion coefficient (D_n) and the diffusion length (L_n) of electrons in the TiO₂ film were acquired. The electron lifetime in the PANI-based DSCs was about 10 times lower than their liquid counterparts, indicating a much more serious recombination of photogenerated electrons in the TiO₂ film, very likely mainly with holes of oxidized dye molecules. With increase in the thickness of TiO₂ film, both τ_n and τ_d decreased, whereas L_n and D_n increased; and the better performance of the solid-state cells was available only in a suitable thickness range of TiO₂ films.