A model for the collection of minority carriers generated in the depletion region of a Schottky barrier solar cell

Abstract

The continuity equation for minority carriers, in this case holes, is solved in the depletion region under the assumption that there is no increase in the recombination rate in the depletion region compared with the rate in the neutral region. The predicted short-circuit current density was found to be between that of the model whereby all the minority carriers generated within and diffusing towards the depletion region are collected and that of the model in which the depletion region is ignored. The current density is strongly dependent on the recombination velocity at the front surface for the back-wall Schottky barrier solar cell and nearly independent of the back-surface recombination velocity for the front-wall solar cell. As a consequence of this dependence, and that of the strong dependence on the semiconductor thickness for the back-wall cell, the front-wall cell appears to be preferable, even though more photon reflection is expected from the front-wall Schottky barrier solar cell. The numerical calculations are for air mass 0 conditions.