Lobato K, Peter L M
Department of Chemistry, University of Bath, Bath BA2 7AY, United Kingdom.
J Phys Chem B. 2006 Nov 2;110(43):21920-3. doi: 10.1021/jp064538o.
A novel type of dye-sensitized cell (DSC) with a passivated titanium sensor electrode located on top of the nanocrystalline titanium dioxide layer has been used to study the temperature dependence of the electron quasi-Fermi level relative to the I3-/I- redox-Fermi level under short circuit conditions. The results show that the Fermi level decreases with increasing temperature (-1.76 meV K(-1)) as predicted for diffusive electron transport at short circuit. A smaller temperature dependence (-0.25 meV K(-1)) of the position of the TiO2 conduction band relative to the I3-/I- redox-Fermi level was deduced from the shifts in the trap distribution. An expression for the temperature dependence of the open circuit voltage, U(photo), has been derived. The experimentally observed temperature dependence of U(photo) gave values of the activation energy (0.25 eV) and preexponential factor (10(8) s(-1)) for the transfer of electrons from the conduction band of the nanocrystalline TiO2 to triiodide ions.
一种新型染料敏化电池（DSC），其钝化钛传感电极位于纳米晶二氧化钛层顶部，已被用于研究短路条件下电子准费米能级相对于I3-/I-氧化还原费米能级的温度依赖性。结果表明，费米能级随温度升高而降低（-1.76 meV K(-1)），这与短路时扩散电子传输的预测一致。根据陷阱分布的变化推断，TiO2导带位置相对于I3-/I-氧化还原费米能级的温度依赖性较小（-0.25 meV K(-1)）。推导了开路电压U(photo)的温度依赖性表达式。实验观察到的U(photo)的温度依赖性给出了电子从纳米晶TiO2导带转移到三碘离子的活化能（0.25 eV）和指前因子（10(8) s(-1)）的值。
