120th General Meeting of the KCS

Type Oral Presentation
Area Oral Presentation for Young Scholars in Polymer Chemistry
Room No. Room 302+303
Time FRI 14:45-:
Code POLY.O-2
Subject The Study on Asymmetric Alkyl Substitution and Application to Hole Transporting Materials for Perovskite Solar Cells
Authors Junwoo Lee, Gyeong Ho Kang, SUNG YUN SON, Taiho Park*
Department of Chemical Engineering, Pohang University of Science and Technology, Korea
Abstract Existing hole transport material in perovskite solar cells has only been applied to toxic solvents such as chlorobenzene due to solubility problems. These solvents result in limitation for the practical use. Therefore, substitution to non-halogen solvents is important to commercialize of perovskite solar cell devices. Here, we studied on asymmetric alkyl substitution to approach high efficient HTMs with green processing. The concept resulted in asymmetry in the monomer itself, leading to irregularity despite being a homopolymer. Amorphous nature from irregularity is one of the method to increase solubility and miscibility. We synthesize and characterize asymmetric polymer named asy-PBTBDT and fabricate hole transport layers using applicable green solvents from Hansen solubility parameters. The green solvent is named 2-methyl anisole that is used in food additives, which is edible and no harmful in human body. The device using asymmetric polymer leads to a PCE of around 20 % using food additive solvent (2-MA) with additives (Li-TFSI and t-BP) and a PCE of 18 % without additives Furthermore, the polymeric HTM leads to longer stability than common spiro-OMeTAD. The polymeric HTM may be a promising material to replace spiro-OMeTAD due to a green processing process for commercialization, stability and high efficiency.
E-mail junwoolee@postech.ac.kr