P-N junction and solar cells

This lecture covers the equations of solar cells, including the dark IV curve of an infinite P-N junction, photocurrent in illuminated solar cells, and the two-diode model. It explains the continuity equations for semiconductor devices and the depletion approximation in the space charge region. The lecture also delves into the electrostatic potential, band diagrams, and built-in voltage in heterojunctions. The concepts are illustrated with examples and calculations for realistic solar cells, emphasizing the impact of bias on band bending and carrier injection. The discussion extends to carrier generation, diffusion, and recombination in illuminated solar cells, as well as the calculation of dark and light I-V curves.