Solar Cells: Band Diagrams and Efficiency

This lecture discusses the principles of a single solar cell, focusing on its band diagrams under different illumination conditions. The instructor explains the structure of a solar cell, including the p-n junction and the role of the load. The lecture covers how illumination generates electron-hole pairs, affecting the depletion region and the built-in voltage. The impact of weak and strong light on the solar cell's performance is analyzed, highlighting the relationship between current and voltage. The instructor compares monocrystalline and amorphous silicon, detailing their respective efficiencies and the trade-offs between current and voltage output. The lecture concludes with a discussion on the maximum efficiency of solar cells, emphasizing the importance of photon energy and thermal losses. Practical applications, such as solar calculators, are also mentioned, illustrating the relevance of solar cell technology in everyday devices.