"Phenothiazine Functionalized Multi-functional A-π-D-π-D-π-A Typed Hole Transporting Materials via Sequential C-H Arylation Approach for Efficient and Stable Perovskite Solar Cells", Chunyuan Lu, M. Paramasivam, Kyutai Park, ChulHoon Kim and Hwan Kyu Kim*, ACS Applied Materials & Interface, 11, 14011-14022 (2019. 03).