Efficiency and power enhancement of solar cells by dark states

Publication date: Available online 2 August 2019Source: Physics Letters AAuthor(s): Sangchul OhAbstractWe study how dark states enhance the efficiency and power of a solar cell as a quantum heat engine. Conventional approaches assume the solar cell is in thermal equilibrium with both hot and cold baths simultaneously. We propose an description that a solar cell is surrounded only by the cold bath and the thermal radiation from the hot bath is described by a pumping term in a master equation. We calculated the current-voltage curve, the power-voltage curve, the efficiency, and the power of the solar cell for different photon fluxes. It is found that as the photon flux increases, the power output increases linearly at first and then becomes saturated, but the efficiency decreases rapidly. It is found that the dark state of the coupled donors of the solar cell enhances the power output significantly at large pumping rates, but the improvement of the efficiency is not strong.

Source: Physics Letters A - August 3, 2019 Category: Physics Source Type: research