Inverted Organic Solar Cells Based on PTB7:PC71BM with PFN Electron Transport Layer on ITO-Free Flexible PEN Substrate
In this paper, we report on the improved long term reliability of similar solar cells with an ITO-free flexibleinverted solar cell structures of PEN/PEDOT:PSS/PFN/(PTB7:PC71BM)/MoO3/Au using, and found these devices showed much improved long-term reliability of the devices stored in air without any surface passivation layer. The J-C characteristics showed a slight reduction in the short cuircuit current density after storage in air for 4 days. The use of the PFN layer also significantly enhanced not only the open-circuit voltages and the power conversion efficiencies of the solar cells presumably due to the high electron transport efficiency and the better contact between the PEDOT:PSS cathode and the PTB7:PC71BM active layer. Although the resulted conversion efficiency was only 1.8% at this moment, and further process improvement will be continued.Furthmore we tried efficiency of the device change in the PFN thickness by spin-coating time.
 Yi-Ming Chang, and Chi-Yi Leu. Journal of Materials Chemistry A 1.21 (2013): 6446-6451.