As‐Cast Ternary Organic Solar Cells Based on an Asymmetric Side‐Chains Featured Acceptor with Reduced Voltage Loss and 14.0% Efficiency
Abstract
A new small‐molecule nonfullerene acceptor based on the benzo[1,2‐b:4,5‐b′]dithiophene (BDT) fused central core with asymmetrical alkoxy and thienyl side chains, namely TOBDT, is designed and synthesized. The alkoxy unit helps narrow the bandgap, and thienyl side chain helps enhance the intermolecular interaction. As a result, TOBDT is suitable to match the deep‐lying highest occupied molecular orbital (HOMO) of polymer donor PM6. Then, a strong crystalline acceptor IDIC is introduced as the third component to fabricate as‐cast nonfullerene ternary devices to achieve absorption and morphology control. Addition of IDIC not only mixes well with TOBDT but modulates the morphology of the blend film, which helps to balance the charge transport properties and reduce the photovoltage loss of ternary devices. All these contribute to synergetic improvement of Jsc, Voc, and fill factor parameters, leading to a power conversion efficiency of 14.0% for the as‐cast fullerene‐free ternary device.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jan 22, 2020
- Source ID
- 10.1002/adfm.201909535
Entities
People
- Alex K.‐y. Jen
- Bin Kan
- Feng Liu
- Francis Lin
- Ke Gao
- Ming Zhang
- Sae Byeok Jo
- Xiaobin Peng
- Xuebin Chen
- Yong Cao
- Yuanyuan Kan
Organizations
- City University of Hong Kong
- National Natural Science Foundation of China
- Office of Naval Reactors
- Office of Naval Research
- Program 973
- Shanghai Jiao Tong University
- University of Washington