Polymerizable Ionic liquids as a dopent in polymer based photovoltaic devices employing a chemically fixed p-I-n junction

Abstract

The high cost of silicon-based photovoltaic devices is currently limiting their promise as a viable replacement to fossil fuel. Recent research in polymer-based photovoltaics has received significant attention as a possible affordable solar energy technology. In particular, research on chemically fixed p-i-n junctions in polymer based thin film photovoltaics has shown promising results. These devices work by blending ionic monomers into a polymer film and placing them between two electrodes. These monomers respond to an applied bias resulting in electrochemical doping occurring at the electrodes ending with a fixed p-i-n junction. Devices demonstrate promising open circuit voltages but suffer from low power conversion efficiency and extensive charging time. Recently it was demonstrated in light-emitting electrochemical cells that substituting ionic monomers with polymerizable ionic liquids significantly reduces charge time without affecting device performance. Here, we use these PILs to create a fixed p-I-n junction photovoltaic device. These devices are demonstrating some of the highest open circuit voltages seen in polymer PV devices. We will discuss strategies for optimizing overall device performance in order to achieve a low-cost, high performance polymer photovoltaic technology