Efficient Semitransparent Solar Cells with High NIR Responsiveness Enabled by a Small‐Bandgap Electron Acceptor
Abstract
Inspired by the remarkable promotion of power conversion efficiency (PCE), commercial applications of organic photovoltaics (OPVs) can be foreseen in near future. One of the most promising applications is semitransparent (ST) solar cells that can be utilized in value‐added applications such as energy‐harvesting windows. However, the single‐junction STOPVs utilizing fullerene acceptors show relatively low PCEs of 4%–6% due to the limited sunlight absorption because it is a dilemma that more photons need to be harvested in UV–vis–near‐infrared (NIR) region to generate high photocurrent, which leads to the significant reduction of device transparency. This study describes the development of a new small‐bandgap electron‐acceptor material ATT‐2, which shows a strong NIR absorption between 600 and 940 nm with an Egopt of 1.32 eV. By combining with PTB7‐Th, the as‐cast OPVs yield PCEs of up to 9.58% with a fill factor of 0.63, an open‐circuit voltage of 0.73 V, and a very high short‐circuit current of 20.75 mA cm−2. Owing to the favorable complementary absorption of low‐bangap PTB7‐Th and small‐bandgap ATT‐2 in NIR region, the proof‐of‐concept STOPVs show the highest PCE of 7.7% so far reported for single‐junction STOPVs with a high transparency of 37%.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Mar 21, 2017
- Source ID
- 10.1002/adma.201606574
Entities
People
- Cheng Zhang
- Feng Liu
- Jianyun Zhang
- Q. Hu
- Thomas Paul Russell
- Thomas Vergote
- Xiaozhang Zhu
- Zichun Zhou
Organizations
- Institute of Chemistry
- Lawrence Berkeley National Laboratory
- National Natural Science Foundation of China
- Office of Naval Research
- Shanghai Jiao Tong University
- University of Chinese Academy of Sciences
- University of Massachusetts