Donor Derivative Incorporation: An Effective Strategy toward High Performance All‐Small‐Molecule Ternary Organic Solar Cells

• DOI: 10.1002/advs.201901613
• Publication Date: 2019-09-04T08:50:44Z
• Authors: Hua Tang; Tongle Xu; Cenqi Yan; Jie Gao; Hang Yin; Jie Lv; Ranbir Singh; Manish Kumar; Tainan Duan; Zhipeng Kan; Shirong Lu; Gang Li
• Keywords: Terthiophene; Derivative (finance)

Abstract Thick‐film all‐small‐molecule (ASM) organic solar cells (OSCs) are preferred for large‐scale fabrication with printing techniques due to the distinct advantages of monodispersion, easy purification, and negligible batch‐to‐batch variation. However, ASM OSCs typically constrained by morphology aspect achieve high efficiency maintain thick film simultaneously. Specifically, synchronously manipulating crystallinity, domain size, phase segregation a suitable level extremely challenging. Herein, derivative benzodithiophene terthiophene rhodanine (BTR) (a successful small molecule donor thick‐film OSCs), namely, BTR‐OH, is synthesized similar chemical structure absorption but less crystallinity relative BTR, employed as third component construct BTR:BTR‐OH:PC 71 BM ternary devices. The power conversion (PCE) 10.14% fill factor (FF) 74.2% successfully obtained in ≈300 nm OSC, which outperforms BTR:PC (9.05% 69.6%) BTR‐OH:PC (8.00% 65.3%) counterparts, stands among top values OSCs. performance enhancement results from enhanced absorption, suppressed bimolecular/trap–assisted recombination, improved charge extraction, optimized crystallinity. These findings demonstrate that featuring different provides promising guideline high‐performance