Indium Tin Oxide-Free Polymer Solar Cells: Toward Commercial Reality
In Green Energy and Technology, 2014
Abstract
Polymer solar cell (PSC) is the latest of all photovoltaic technologies which currently lies at the brink of commercialization. The impetus for its rapid progress in the last decade has come from low-cost high throughput production possibility which in turn relies on the use of low-cost materials and vacuum-free manufacture. Indium tin oxide (ITO), the commonly used transparent conductor, imposes the majority of the cost of production of PSCs, limits flexibility, and is feared to create bottleneck in the dawning industry due to indium scarcity and the resulting large price fluctuations. As such, finding a low-cost replacement of ITO is widely identified to be very crucial for the commercial feasibility of PSCs. In this regard, a variety of nanomaterials have shown remarkable potential matching up to and sometimes even surpassing the properties of ITO. This chapter elaborates the recent developments in ITO replacement which include, but are not limited to, the use of nanomaterials such as metal nanogrids, metal nanowires, carbon nanotubes, and graphene. The use of polymers and metals as replacement to ITO are described as well. Finally, recent progress in large-scale experiments on ITO-free PSC modules is also presented.