Influence of interfacial area on exciton separation and polaron recombination in nanostructured bilayer all-polymer solar cells.
Influence of interfacial area on exciton separation and polaron recombination in nanostructured bilayer all-polymer solar cells.
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DOI：
10.1021/nn5064166
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发表时间：
2014-11
期刊：
影响因子：
17.1
通讯作者：
T. Pfadler;Mihael Coric;C. M. Palumbiny;Andreas C. Jakowetz;K. Strunk;J. Dorman;P. Ehrenreich;Cheng Wang;A. Hexemer;Rui‐Qi Png;P. Ho;P. Müller‐Buschbaum;J. Weickert;L. Schmidt‐Mende
中科院分区：
文献类型：
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作者：
T. Pfadler;Mihael Coric;C. M. Palumbiny;Andreas C. Jakowetz;K. Strunk;J. Dorman;P. Ehrenreich;Cheng Wang;A. Hexemer;Rui‐Qi Png;P. Ho;P. Müller‐Buschbaum;J. Weickert;L. Schmidt‐Mende
有机太阳能电池的宏观器件性能受纳米尺度的界面物理控制。采用梳状双层全聚合物形态作为模型系统，研究这些器件中激子分离和极化子复合的基本过程，其特征是供体-受体界面面积受控增强。通过 SEM/AFM 对不同的纳米结构进行局部表征，并通过先进的掠入射 X 射线散射技术在大面积上对最终器件架构的埋置叉指界面进行统计验证。结果表明，供体和受体材料中光激子的收获同样增强，与界面面积的总体增强直接相关。除了这种有益效果之外，增强的界面还导致开路电压和最大功率点周围的极化子复合损耗显着增加，这是与二极管暗电流特性、阻抗谱和瞬态光电压测量相补充而确定的。根据这些发现，可以推断，尽管经常假设，但空间优化的梳状供体-受体纳米网络本身并不是理想的形态。相反，必须考虑充满活力的景观。激子太阳能电池的完美形态必须在施主-受主界面的空间和能量上进行优化。
The macroscopic device performance of organic solar cells is governed by interface physics on a nanometer scale. A comb-like bilayer all-polymer morphology featuring a controlled enhancement in donor-acceptor interfacial area is employed as a model system to investigate the fundamental processes of exciton separation and polaron recombination in these devices. The different nanostructures are characterized locally by SEM/AFM, and the buried interdigitating interface of the final device architecture is statistically verified on a large area via advanced grazing incidence X-ray scattering techniques. The results show equally enhanced harvesting of photoexcitons in both donor and acceptor materials directly correlated to the total enhancement of interfacial area. Apart from this beneficial effect, the enhanced interface leads to significantly increased polaron recombination losses both around the open-circuit voltage and maximum power point, which is determined in complement with diode dark current characteristics, impedance spectroscopy, and transient photovoltage measurements. From these findings, it is inferred that a spatially optimized comb-like donor-acceptor nanonetwork alone is not the ideal morphology even though often postulated. Instead, the energetic landscape has to be considered. A perfect morphology for an excitonic solar cell must be spatially and energetically optimized with respect to the donor-acceptor interface.