Systematic anode engineering enabling universal efficiency improvements in organic solar cells
Kwok Kiu Tsang,
Han Yu,
Joshua Yuk Lin Lai,
Ho Ming Ng,
Chung Hang Kwok,
Wenzhao Xiong,
Huawei Hu,
He Yan
Affiliations
Kwok Kiu Tsang
Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, 999077, China
Han Yu
Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, 999077, China; Guangdong-Hong Kong Joint Laboratory for Carbon Neutrality Jiangmen Laboratory of Carbon Science and Technology, Jiangmen, Guangdong Province 529199, China; Corresponding authors.
Joshua Yuk Lin Lai
Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, 999077, China
Ho Ming Ng
Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, 999077, China
Chung Hang Kwok
Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, 999077, China
Wenzhao Xiong
State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, China
Huawei Hu
State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, China
He Yan
Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, 999077, China; Guangdong-Hong Kong Joint Laboratory for Carbon Neutrality Jiangmen Laboratory of Carbon Science and Technology, Jiangmen, Guangdong Province 529199, China; Corresponding authors.
Anode modification and optimization is crucial towards improving performance of organic solar cells (OSCs). PEDOT:PSS is the most common choice as a hole transport layer (HTL) material, but suffers from issues including low conductivity. In this work, three alkyl amine derivatives - methylamine hydrochloride (MA), ethylamine hydrochloride (EA) and propylamine hydrochloride (PA) are doped into the commercially available Al 4083 PEDOT:PSS to form PEDOT:PSS-MA, PEDOT:PSS-EA and PEDOT:PSS-PA, as modified HTLs. All these modified HTLs exhibit improved chemical and electrical properties including work functions (WF), conductivities and charge carrier motilities. The alkyl amine doping shows compatibility in both Small Molecular Acceptors and All-Polymer OSCs. With PEDOT:PSS-MA demonstrates a highest PCE of 18.49 % compared to the 17.84 % of OSC devices prepared with pristine PEDOT:PSS with the PM6:L8-BO system, while PM6:PY-IT all-polymer OSCs improve PCE from 14.53 % to 15.22 %. AFM characterizations reveal that the introduction of the dopants have smoothened the surface morphology of spin-coated HTL films, which contributes towards more efficient charge extraction. In summary, this study not only presents a method of improving OSC efficiencies, but also provides insight and further possible directions towards anode optimization of OSCs.
