3D Optical and device simulation of surface plasmonic effects on organic solar cells using silver nano prisms

We explore the enhancement of light absorption due to triangle-shaped silver nanoprisms in P3HT:PCBM active layer and its impact on organic solar cell performance by coupling optical and electronic device simulation. We use optical simulation via FDTD solution of Maxwell´s equations in order to calculate the surface plasmonic resonance at the interface of P3HT:PCBM and silver nanoprisms. The presence of silver nanoprisms results in dramatic local enhancement of optical absorption. We explore different design of silver nanoprisms by changing sizes, densities, and relative orientations to see their impact on optical carrier generation. From the device modeling point of view, a thinner active layer enabled by enhanced absorption reduces the mismatch of light absorption depth with exciton dissociation length. We use the Sentaurus Device simulator (Synopsys®), adapted with material-specific models for electronic polymers, to explore the impact of surface plasmon resonance on device behavior. The coupling of optical and electrical simulation gives a short-circuit current increase of 3 times for 35nm ultra-thin active layer with silver nanoprisms, consistent with experiment^[1].