To commercialize organic solar cells (OSCs), changes in the optimized morphology of the photoactive layer caused by external stimuli that cause degradation must be addressed. This work improves OSC stability by utilizing the cross-linking additive 1,8-dibromooctane (DBO) and a sequential deposition process (XSqD) to fabricate the photoactive layer. The cross-linking additive in the donor polymer (PTB7-Th) improves polymer crystallinity and immobilizes the crystalline morphology by partial photo-cross-linking. Ellipsometry experiments confirm the increase in the glass transition temperature of cross-linked PTB7-Th. The polymer crystallinity is further improved after removal of non-cross-linked polymer and residual additive by chlorobenzene. The cross-linked polymer layer forms an efficient and stable heterojunction with a nonfullerene acceptor (IEICO-4F) layer via an XSqD process. The OSC based on the immobilized PTB7-Th exhibits excellent stability against light soaking and thermal aging.
|Number of pages||13|
|Journal||ACS Applied Materials and Interfaces|
|Publication status||Published - 2022 May 25|
Bibliographical noteFunding Information:
This research was supported by a National Research Foundation of Korea (NRF) Grant funded by the Ministry of Science, ICT and Future Planning (NRF-2019M1A2A2072417, NRF-2021R1A2C2006588, NRF-2020R1A6A1A03038697, and NRF-2020R1A2C1101905).
© 2022 American Chemical Society. All rights reserved.
All Science Journal Classification (ASJC) codes
- Materials Science(all)