ABSTRACT
This chapter provides an overview of Organic solar cells (OSCs) from the basics to the state-of-art research frontiers, and introduces structures and operation principle of OSCs, and discusses development of materials for high-performance OSCs. An OSC device consists of three important components: photoactive layer, electrodes, and interfacial layers. OSCs or organic photovoltaics are fabricated in a layered structure. Impressive progress has been achieved using solution-processed conjugated polymers as donor material. Even the early-stage OSC research started from investigating vacuum-evaporated small-molecule materials, conjugated polymers as donor dominated the field since 1990s. The similar strategies are shared between designing conjugated small molecules and polymers, and we discuss and classify the D-A small molecules based on the most common moieties. Hole-selective interfacial layers should have high work functions to match the highest occupied molecular orbital level of donor polymer.
