Dual mode OPV-OLED device with photovoltaic and light-emitting functionalities
Takayuki Chiba, Daichi Kumagai, Kazuo Udagawa, Yuichiro Watanabe, Junji Kido
Scientific Reports, 8: 11472 (2018)
The rapid development of organic optoelectronic devices such as organic photovoltaics (OPVs) and organic light-emitting devices (OLEDs) is largely attributable to their advantageous properties of their large area, ultrathin thickness, flexiblility, transparency, and solution processability. Herein, we fabricate and characterize a dual mode OPV-OLED device with three-terminal structure comprising a polymer-based bulk-heterojunction inverted OPV unit and a top-emission white phosphorescent OLED unit back-to-back connected via intermediate metal alloy electrode. Sputter-deposited indium tin oxide was used as a transparent cathode of the inverted OPV unit, whereas Ag-doped Al served as a common OPV/OLED anode, allowing the decoupling of electricity generation and light mission functions. Notably, the doping of Al by Ag facilitated the reduction of surface roughness, allowing the above electrode to be used as a common anode and dramatically reducing the leakage current. Finally, the top-emission OLED unit featured an ultrathin layer of Ag-doped Mg as a semitransparent cathode. Thus, successful integration of the OPV-OLED elements results in the decoupling of electricity generation and light emission functionalities, achieving a power conversion efficiency of 3.4% and an external quantum efficiency of 9.9%.