This document discusses solar energy and solar cells. It begins by introducing solar energy and its benefits of being clean, silent and providing convenient installation. It then defines solar cells and solar panels, explaining that they convert sunlight into electricity via the photovoltaic effect. The document outlines the basic construction and working of solar cells, including their layered structure. It describes the main types of solar cells as mono-crystalline, poly-crystalline and thin film. Applications of solar energy are also listed, such as for street lighting, water pumping, and solar homes. The document concludes by discussing future prospects of increasing solar cell efficiency and reducing costs to make solar energy more widespread.