1. Versatile control of concentration gradients in non-fullerene acceptor-based bulk heterojunction films using solvent rinse treatments
- Author
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Sung Heum Park, In-Wook Hwang, Jihoon Lee, Chang-Mok Oh, and Soyeong Jang
- Subjects
Materials science ,Organic solar cell ,Renewable Energy, Sustainability and the Environment ,Electron donor ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Acceptor ,Polymer solar cell ,0104 chemical sciences ,Contact angle ,Solvent ,chemistry.chemical_compound ,PEDOT:PSS ,chemistry ,Chemical engineering ,Chlorobenzene ,0210 nano-technology - Abstract
Solvent rinse treatments using polar methanol (MeOH) and nonpolar n-hexane have been developed for controlling material concentration gradients along the longitudinal direction of non-fullerene acceptor-based bulk heterojunction (BHJ) films comprised of electron donor polymer, PBDB-T and acceptor, ITIC-m. Before the used solvents (chlorobenzene with 1 vol.% DIO) were completely evaporated, ITIC-m rich domains were formed at the top surface of the BHJ films after they were rinsed with MeOH, as evidenced by water contact angle, atomic force microscopy, time-of-flight secondary ion mass spectroscopy, which led to enhanced electron transport in the conventional structure of organic solar cells (OSCs). In contrast, after rinsing with n-hexane, ITIC-m rich domains were formed at the bottom surface of the films, which improved electron transport in the inverted structure OSCs. The enhanced carrier transports increased the PCEs (11.80% and 11.15%) in both conventional and inverted OSCs by 10.29% and 10.35% compared with control devices. The versatile control of material concentration gradients is determined to be feasible owing to the chemical interaction of the used substrates (glass, PEDOT:PSS, and ZnO) and rinsing solvents.
- Published
- 2022