Design Considerations for Efficient and Stable Polymer Solar Cells

Organic photovoltaics (OPVs) are gaining more interest due to their potential for low fabrication cost, mechanical fl exibility and light weight. Not long ago, lower power conversion effi ciency and inferior stability compared to their inorganic counterparts were considered major issues associated with OPVs. Today, OPVs with an effi ciency as high as 12% have been achieved and stability under ambient conditions has also been signifi cantly improved, especially with the devices using inverted architecture. A major advantage of using OPVs over traditional thin fi lm inorganic solar cells with comparable effi ciency (~14-15%), is their excellent performance in real-life environments like high temperature and low light conditions. In this chapter, we discuss recent advances in realizing high performance and stable OPV devices. The chapter consists of three major parts: the role of interfacial layer for effi cient Bulk heterojunction (BHJ) solar cells, the selection of interfacial layer for stable and longer life time OPVs and major interfacial materials used for conventional and inverted device architectures.