Proceedings of International Conference on Perovskite and Organic Photovoltaics and Optoelectronics (IPEROP19)
DOI: https://doi.org/10.29363/nanoge.iperop.2019.022
Publication date: 23rd October 2018
It is often a great challenge to achieve optimal performance in organic photovoltaic devices (OPVs) because of the limited control over the arrangement of constituent materials in the active layer. In this connection, we are exploring the potential of a unique “photoprecursor approach” for controlled deposition of small-molecule organic semiconductors [1–3]. This approach employs α-diketone (DK)-type derivatives of acenes as solution-processable precursors that can be cleanly converted to corresponding acene compounds upon visible-light irradiation. The conversion of DK-type photoprecursors is generally accompanied with a considerable decrease in solubility, and when the solubility of resulting acene is sufficiently low, one can deposit another material on top of it via a solution process for constructing a multilayer structure. We have applied this sequential solution deposition to the preparation of ternary OPV active layers with a controlled vertical composition profile [4]. The resulting devices showed an approximately two times higher power-conversion efficiency as compared to the corresponding binary bulk-heterojunction system. This work opens up new possibilities in designing materials and active layers for solution-processed OPVs and other organic electronic devices.
This research was supported by the CREST program of the Japan Science and Technology Agency (JST), Grants-in-Aid for Scientific Research (KAKENHI) (No. JP26105004, JP16H02286, JP16K17949 and JP17H03134) from the Japan Society for the Promotion of Science (JSPS), Japan Regional Innovation Strategy Program by the Excellence (J-RISE) sponsored by JST, NAIST foundation, Izumi science and technology foundation, and the program for promoting the enhancement of research universities in NAIST supported by MEXT.