Determination of the maximum efficiency solar cell structure

A very general formulation of a semiconducting photovoltaic device is given. The efficiency of this device is maximized with respect to tis structural parameters. In this way it is shown that no solar cell structure can achieve a large efficiency than an infinite tandem cell, with bandgaps monotonically decreasing from infinity to zero, and of which each individual cell is a selective black body with its own appropriate bias voltage. This maximum efficiency is numerically calculated for various cell- and sun temperatures and concentration factors.