Investigation of Mechanical Flexibility of Slot Die Coated PEDOT:PSS Nano-Films for Indium Tin Oxide-Free Flexible Organic Solar Cells

摘要

We investigated the mechanical flexibility of slot die coated poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) films to apply in cost-effective indium tin oxide (ITO)-free flexible organic solar cells (FOSCs) as a flexible electrode. The mechanical properties of 100 and 400 nm-thick PEDOT:PSS films coated on flexible PET substrates were comprehensively investigated using several bending modes such as outer/inner bending, twisting, and rolling. In several bending tests, the 100 and 400 nm thick PEDOT:PSS films shows superior mechanical flexibility than amorphous ITO film. In addition, we investigated the surface of the PEDOT:PSS film and amorphous ITO films after outer bending test to compare failure mechanism. FOSCs fabricated on the PEDOT:PSS anode showed a higher power conversion efficiencies of 3.257% than that (1.630%) of the FOSC with amorphous ITO film. Better performances of FOSC with the PEDOT:PSS anode indicates that slot die coated PEDOT:PSS film is a promising candidate to substitute amorphous ITO film for realizing cost effective and high performance FOSCs due to its simple printing process and superior flexibility.