Enhanced Performance and Stability of Polymer BHJ Photovoltaic Devices from Dry Transfer of PEDOT: PSS

초록

Polymer solar cells with enhanced initial cell performances and long-term stability were fabricated by performing a simple dry transfer of a hole extraction layer [poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT: PSS)] onto an indium tin oxide (ITO) substrate. Due to the very flat surface of the polyurethane acrylate/polycarbonate (PUA/PC) film, which was used as a mold and resembled the surface of the original substrate (silicon wafer), the transferred layer had a very smooth surface morphology, resulting in enhancement of the interfacial characteristics. The work function of the PEDOT: PSS layer and the morphology of bulk hetero junction (BHJ) layer were tuned by controlling the position of PSS enrichment in the PEDOT: PSS layer using the dry transfer. The power conversion efficiency of PTB7:PC71BM BHJ device prepared by the dry transfer was 8.06 %, which was significantly higher than that of the spin-cast device (7.32 %). By avoiding direct contact between the ITO substrate and the PEDOT: PSS solution in the dry transfer system, etching and diffusion of indium in the ITO substrate were greatly reduced, thereby improving the stability.

키워드