Enabling High‐Performance Tandem Organic Photovoltaic Cells by Balancing the Front and Rear Subcells
Abstract
In tandem organic photovoltaics, the front subcell is based on large‐bandgap materials, whereas the case of the rear subcell is more complicated. The rear subcell is generally composed of a narrow‐bandgap acceptor for infrared absorption but a large‐bandgap donor to realize a high open‐circuit voltage. Unfortunately, most of the ultraviolet–visible part of the photons are absorbed by the front subcell; as a result, in the rear subcell, the number of excitons generated on large‐bandgap donors will be reduced significantly. This reduces the (photo) conductivity and finally limits the hole‐transporting property of the rear subcell. In this work, a simple and effective way is proposed to resolve this critical issue. To ensure sufficient photogenerated holes in the rear subcell, a small amount of an infrared‐absorbing polymer donor as a third component is introduced, which provides a second hole‐generation and transporting mechanism to minimize the aforementioned detrimental effects. Finally, the short‐circuit current density of the two‐terminal tandem organic photovoltaic is significantly enhanced from 10.3 to 11.7 mA cm−2 (while retaining the open‐circuit voltage and fill factor) to result in an enhanced power conversion efficiency of 15.1%.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Aug 16, 2020
- Source ID
- 10.1002/adma.202002315
Entities
People
- Chenhui Zhu
- Chung‐hao Chen
- Dong Meng
- Hao‐cheng Wang
- Kung‐hwa Wei
- Pei Cheng
- Ran Zheng
- Rui Wang
- Shuixing Dai
- Xiaowei Zhan
- Yang Yang
- Yepin Zhao
- Yuan Zhu
- Zeyuan Li
Organizations
- Air Force Office of Scientific Research
- California Energy Commission
- Lawrence Berkeley National Laboratory
- National Chiao Tung University
- National Natural Science Foundation of China
- Peking University