Overcoming the Interfacial Photocatalytic Degradation of Nonfullerene Acceptor-Based Organic Photovoltaics by Introducing a UV-A-Insensitive Titanium Suboxide Layer

• Published in: ACS applied materials & interfaces 2024-01, Vol.16 (3), p.3778-3785
• Main Authors: Park, Kiyoung, Kim, Ju-Hyeon, Jin, Jong Sung, Moon, Heehun, Oh, Juhui, Lee, Sanseong, Ki, Taeyoon, Jeong, Hyeon-Seok, Jeong, Soyeong, Jang, Soo-Young, Kang, Hongkyu, Lee, Kwanghee
• Format: Article
• Language: English
• Subjects: Organic Electronic Devices
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.3c15801

Although recent dramatic advances in power conversion efficiencies (PCEs) have resulted in values over 19%, the poor photostability of organic photovoltaics (OPVs) has been a serious bottleneck to their commercialization. The photocatalytic effect, which is caused by incident ultraviolet-A (UV-A, 320–400 nm) light in the most commonly used zinc oxide (ZnO X ) electron transport layer (ETL), significantly deteriorates the photostability of OPVs. In this work, we develop a new and facile method to enhance the photostability of nonfullerene acceptor-based OPVs by introducing UV-A-insensitive titanium suboxide (TiO X ) ETL. Through an in-depth analysis of mass information at the interface between the ETL and photoactive layer, we confirm that the UV-A-insensitive TiO X suppresses the photocatalytic effect. The resulting device employing the TiO X ETL shows excellent photostability, obtaining 80% of the initial PCE for up to 200 h under 1 sun illumination, which is 10 times longer than that of the conventional ZnO X system (19 h).