Thermally stable poly(3‐hexylthiophene): Nonfullerene solar cells with efficiency breaking 10%. Issue 5 (8th March 2022)

• Record Type: Journal Article
• Authors: Gao, Mengyuan; Liu, Yang; Xian, Kaihu; Peng, Zhongxiang; Zhou, Kangkang; Liu, Junwei; Li, Saimeng; Xie, Fei; Zhao, Wenchao; Zhang, Jidong; Jiao, Xuechen; Ye, Long
• Is Part Of: Aggregate. Volume 3:Issue 5(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-03-08
• Subjects: multi‐technique approach -- organic solar cells -- phase separation -- polythiophene -- thermal stability; Aggregation (Chemistry) -- Periodicals; Aggregation (Chemistry); Periodicals; 539.6
• DOI: 10.1002/agt2.190
• Languages: English
• ISSNs: 2692-4560

Abstract

Abstract: Solar cells featuring polythiophenes as donors are one of the optoelectronic devices that hold notable promises for commercial application, profiting from the lowest synthetic complexity and excellent scalability. However, the complex phase behaviors of polythiophenes and their blends put constraints on modulating electrical performance and thus realizing stable performance under thermal stress. In this contribution, we present a multi‐technique approach that combines calorimetry, scattering, spectroscopy, and microscopy to thoroughly probe the thermodynamic mixing, thermal properties of materials, the evolution of nanoscale domain structure, and device performance of poly(3‐hexylthiophene) (P3HT) with a range of nonfullerene acceptors (NFAs) such as ITIC, IDTBR, and ZY‐4Cl. Accordingly, two blending guidelines are established for matching these popular NFAs with P3HT to enable highly efficient and thermally stable cells. First, blend systems with weak vitrification and hypo‐miscibility are excellent candidates for efficient solar cells. Furthermore, high thermal stability can be achieved by selecting NFAs with diffusion‐limited crystallization. The P3HT:ZY‐4Cl blend was found to endow the best performance of over 10% efficiency and an exceptionally high T 80 lifetime of >6000 h under continuous thermal annealing, which are among the highest values for P3HT‐based solar cells. This realization of high thermal stability and efficiency demonstrates the remarkable potentials of simple polythiophene :nonfullerene pairs in electronic applications. Abstract : With the aid of mixing thermodynamics and kinetics vitrification principles, the top efficiency of over 10% and the record‐high T 80 lifetime of >6000 h are realized for low‐cost P3HT solar cells. To construct efficient and thermally stable solar cells, the blend systems should possess weak vitrification, hypo‐miscibility, and diffusion‐limited crystallization of NFAs.