Abstract
Energy conversion devices such as solar cells and fuel cells are considered as highly efficient devices that are capable of transforming and conserving energy directly from the chemical energy into electricity. These are the devices which do not cause evolution of any noxious pollutants to the environment. The different carbon/polymer composites have concerned immense interest as functional components in solar cells and fuel cells as energy conversion applications. In this chapter, the point here is to give initiative about basic perceptive of different types of carbon structured polymer nanocomposites, their characteristic properties, and applications for the fuel cell and solar energy devices.