This document summarizes a seminar presentation on plastic solar cells. It begins with an introduction to plastic solar cells, which were first introduced in 1986 and use conducting plastics and flexible substrates. It then describes conventional solar cells made from semiconductors, which have high efficiency but are expensive to produce. The working principle of a basic p-n junction solar cell is explained. The document then discusses the device architectures, working principles, advantages and drawbacks of plastic solar cells, which use organic semiconductors and conjugated polymers. It concludes by stating that while plastic solar cells are more compact and effective than conventional cells, their current high cost is a major drawback that may be solved in the future.