Enhanced Long-term and Thermal Stability of Polymer Solar Cells in Air at High Humidity with the Formation of Unusual Quantum Dot Networks.
Enhanced Long-term and Thermal Stability of Polymer Solar Cells in Air at High Humidity with the Formation of Unusual Quantum Dot Networks.
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DOI：
10.1021/acsami.7b06145
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发表时间：
2017-07
影响因子：
9.5
通讯作者：
Long Tan;Fan Yang;M. R. Kim;Pandeng Li;Deepak Thrithamarassery Gangadharan;J. Margot;R. Izquierdo;M. Chaker;D. Ma
中科院分区：
文献类型：
--
作者：
Long Tan;Fan Yang;M. R. Kim;Pandeng Li;Deepak Thrithamarassery Gangadharan;J. Margot;R. Izquierdo;M. Chaker;D. Ma
由于聚合物太阳能电池（PSC）的实际应用，其稳定性最近受到越来越多的关注。在此，开发了一种新策略，以大大提高 PSC 在相对较高湿度（50-60％）的空气中的长期稳定性和热稳定性，而无需任何封装。在该策略中，半导体 PbS/CdS 核/壳量子点（QD）被纳入聚（3-己基噻吩）（P3HT）和苯基-C61-丁酸甲酯（PCBM）的光活性混合物中。通过溶液相配体交换，用卤化物配体取代 PbS/CdS QD 表面的初始配体油酸，我们能够在 P3HT:PCBM 薄膜中形成不寻常的、连续的 QD 网络，从而有效地稳定光敏层。基于稳定的 P3HT:PCBM 薄膜的空气处理 PSC 在高湿度下表现出优异的长期稳定性，同时提供超过 3% 的功率转换效率 (PCE)。在没有封装的高湿度空气中储存 30 天后，约 91% 的原始 PCE 被保留。与无 QD 器件的约 53% 保留 PCE 相比，这是一个显着的改进，这可以归因于 P3HT 中 PCBM 聚集和噻吩环氧化的有效抑制，这要归功于强大的 QD 网络的形成。此外，QD网络的存在还能够增强P3HT:PCBM薄膜在高湿度环境（50-60%）下抵抗热应力/氧化的稳定性。该器件在空气中85°C热处理12小时后保持了60%的原始PCE，这比无QD器件高出两倍多。据我们所知，这项工作首次明确证明了光敏层中量子点网络的形成及其对 PSC 稳定性的重要贡献。该策略对于其他基于富勒烯的 PSC 来说非常有前景，并为实现具有高 PCE 和出色稳定性的 PSC 开辟了新途径。
Due to the practical applications of polymer solar cells (PSCs), their stability recently has received increasing attention. Herein, a new strategy was developed to largely enhance the long-term and thermal stability of PSCs in air with a relatively high humidity of 50-60% without any encapsulation. In this strategy, semiconductor PbS/CdS core/shell quantum dots (QDs) were incorporated into the photoactive blend of poly(3-hexylthiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM). By replacing the initial ligands of oleic acid with halide ligands on the surface of PbS/CdS QDs via solution-phase ligand exchange, we were able to form unusual, continuous QD networks in the film of P3HT:PCBM, which effectively stabilized the photoactive layer. Air-processed PSCs based on the stabilized P3HT:PCBM film showed excellent long-term stability under high humidity, providing over 3% of power conversion efficiency (PCE) simultaneously. Around 91% of pristine PCE was retained after 30 days storage in high-humidity air without encapsulation. This constitutes a remarkable improvement compared to ∼53% retained PCE for the QD-free devices, which can be ascribed to the efficient suppression of both PCBM aggregation and oxidation of the thiophene ring in P3HT, thanks to the formation of robust QD networks. Furthermore, the presence of QD networks was able to enhance the stability of the P3HT:PCBM film against thermal stress/oxidation under high-humidity environment (50-60%) as well. The device kept 60% of pristine PCE after thermal treatment for 12 h at 85 °C in air, which is more than twice higher than that for the QD-free device. To the best of our knowledge, the work represents the first unambiguous demonstration of the formation of QD networks in the photoactive layer and of their important contribution to the stability of PSCs. This strategy is highly promising for other fullerene-based PSCs and opens a new avenue toward achieving PSCs with high PCE and excellent stability.