Balance between Energy Transfer and Exciton Separation in Ternary Organic Solar Cells with Two Conjugated Polymer Donors,ACS Applied Energy Materials

当前位置： X-MOL 学术 › ACS Appl. Energy Mater. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Balance between Energy Transfer and Exciton Separation in Ternary Organic Solar Cells with Two Conjugated Polymer Donors
ACS Applied Energy Materials ( IF 5.4 ) Pub Date : 2020-05-13 00:00:00 , DOI: 10.1021/acsaem.0c00740
Leiping Duan ₁ , Yu Zhang ₁ , Rong Deng ₁ , Haimang Yi ₁ , Ashraf Uddin ₁

Affiliation

The ternary strategy as a straightforward way for organic solar cells to improve the device performance attracts many interests in the field. The ternary strategy usually focuses on processing the third light-absorbing material having a complementary absorption to the binary system. However, studying the third component with similar absorption spectra as those of the binary counterpart is equally essential to understand the in-depth mechanism of the performance improvement from the third component. In this work, we filled this blank and derived a type of ternary device consisting of two conjugated polymer donor materials of PTB7-Th and PffBT4T-2OD and the nonfullerene acceptor material IEICO-4F. The average power conversion efficiency value of the optimized ternary device reached 12.1%, which is around 16% higher than that of its PTB7-Th:IEICO-4F binary counterpart. For the third component of PffBT4T-2OD containing a similar absorption spectrum as that of PTB7-Th, it was found that the J_sc increase contributes to the primary performance enhancement. Further investigations indicate that the J_sc increase in the optimized ternary device mainly came from the improved light absorption ability, current extraction process, charge transport process, and suppressed nonradiative recombination. Moreover, there is a balance found between the exciton separation process and the energy transfer process when optimizing ternary blend ratios. The optimized ternary device is suspected to reach this balance point and thus exhibits the enhancement in device performance. Morphology investigation reveals that the addition of PffBT4T-2OD can tune the morphology and increase the crystallinity in the active layer. The optimized ternary blend shows a well-mixed donor and acceptor morphology with small domain size and slightly increased crystallization, which further explains its best device performance.

中文翻译：

具有两个共轭聚合物供体的三元有机太阳能电池中能量转移和激子分离之间的平衡

三元策略作为有机太阳能电池改善设备性能的直接方法吸引了该领域的许多兴趣。三元策略通常集中于处理对二元体系具有互补吸收的第三光吸收材料。然而，研究具有与二元对应物相似的吸收光谱的第三组分对于理解第三组分的性能改善的深入机理同样重要。在这项工作中，我们填补了这一空白，并得出了一种三元装置，该三元装置由两种共轭聚合物供体材料PTB7-Th和PffBT4T-2OD和非富勒烯受体材料IEICO-4F组成。经过优化的三元器件的平均功率转换效率值达到12.1％，比其PTB7-Th高出约16％：IEICO-4F二进制副本。对于具有与PTB7-Th相似的吸收光谱的PffBT4T-2OD的第三种成分，发现J _sc的增加有助于提高主要性能。进一步的调查表明，J _sc优化的三元器件的增加主要归因于光吸收能力，电流提取过程，电荷传输过程的改善以及非辐射复合的抑制。而且，当优化三元混合比时，在激子分离过程和能量转移过程之间找到平衡。怀疑优化的三元器件已达到此平衡点，因此显示出器件性能的增强。形态学研究表明，添加PffBT4T-2OD可以调节活性层的形态并增加其结晶度。优化的三元共混物显示出良好混合的供体和受体形态，具有较小的畴尺寸和稍微增加的结晶度，这进一步解释了其最佳的器件性能。

更新日期：2020-05-13

点击分享查看原文

点击收藏

阅读更多本刊新发论文本刊介绍/投稿指南