Impact of Molecular Charge-Transfer States on Photocurrent Generation in Solid State Dye-Sensitized Solar Cells Employing Low-Band-Gap Dyes
Impact of Molecular Charge-Transfer States on Photocurrent Generation in Solid State Dye-Sensitized Solar Cells Employing Low-Band-Gap Dyes
复制标题
分子电荷转移态对采用低带隙染料的固态染料敏化太阳能电池中光电流产生的影响
DOI：
10.1021/jp5000667
复制
发表时间：
2014
期刊：
影响因子：
--
通讯作者：
Raavi S
中科院分区：
文献类型：
--
作者：
Raavi S
“推拉”结构被认为是设计全有机分子作为染料敏化太阳能电池（DSSC）敏化剂的制胜策略。在这项工作中，我们表明，当光激发的总能量太低而无法拦截 TiO2 光阳极中的接受态时，具有强电荷转移特性的分子激发态的存在可能对于电荷产生至关重要。尽管空穴转移到 2,2',7,7'-四(N,N-二-对甲氧基苯胺)-9,9'-螺二芴的速度非常快，但电子空穴对很可能在有机界面处形成，从而导致可能的陷阱激发。这导致固态 DSSC (ss-DSSC) 器件中的光电流生成较差。我们证明可以通过制造基于 SnO2 的 ss-DSSC 来克服这个问题。由此产生的太阳能电池首次表明，当使用基于苝的低带隙推拉染料作为敏化剂时，基于 SnO2 的 ss-DSSC 的性能优于基于 TiO2 的太阳能电池。
“Push–pull” structures have been considered a winning strategy for the design of fully organic molecules as sensitizers in dye-sensitized solar cells (DSSC). In this work we show that the presence of a molecular excited state with a strong charge-transfer character may be critical for charge generation when the total energy of the photoexcitation is too low to intercept accepting states in the TiO2photoanode. Though hole transfer to the 2,2′,7,7′-tetrakis(N,N-di-p-methoxyphenylamine)-9,9′-spirobifluorene can be very fast, an electron–hole pair is likely to form at the organic interface, resulting in a possible traplike excitation. This leads to poor photocurrent generation in the solid state DSSC (ss-DSSC) device. We demonstrate that it is possible to overcome this issue by fabricating SnO2-based ss-DSSC. The resulting solar cell shows, for the first time, that a SnO2-based ss-DSSC can outperform a TiO2-based one when a perylene-based, low-band-gap, push–pull dye is used as sensitizer.
影响因子：
15
作者：
Koops, Sara E.;O'Regan, Brian C.;Durrant, James R.
通讯作者：
Durrant, James R.
影响因子：
15
作者：
NAZEERUDDIN, MK;KAY, A;GRATZEL, M
通讯作者：
GRATZEL, M
影响因子：
10.8
作者：
Snaith, Henry J.;Ducati, Caterina
通讯作者：
Ducati, Caterina