@article {Bremner2008, title = {Analysis of tandem solar cell efficiencies under {AM1.5G} spectrum using a rapid flux calculation method}, journal = {Progress in Photovoltaics: Research and Applications}, volume = {16}, number = {3}, year = {2008}, pages = {225{\textendash}233}, abstract = {

We report the use of a rapid flux calculation method using incomplete Riemann zeta functions as a replacement for the {Bose-Einstein} integral in detailed balance calculations to study the efficiency of tandem solar cell stacks under the terrestrial {AM1.5G} spectrum and under maximum concentration. The maximum limiting efficiency for unconstrained and constrained tandem stacks of up to eight solar cells, under the {AM1.5G} spectrum and maximum concentration, are presented. The results found agree well with previously published results with one exception highlighting the precautions necessary when calculating for devices under the {AM1.5G} spectrum. The band gap sensitivities of two tandem solar cell stack arrangements of current interest were also assessed. In the case of a three solar cell tandem stack the results show a large design space and illustrate that the constrained case is more sensitive to band gap variations. Finally, the effect of a non-optimum uppermost band gap in a series constrained five solar cell tandem stack was investigated. The results indicate that a significant re-design is only required when the uppermost band gap is greater than the optimum value with a relatively small effect on the limiting efficiency. It is concluded that this rapid flux calculation method is a powerful tool for the analysis of tandem solar cells and is particularly useful for the design of devices where optimum band gaps may not be available. Copyright \© 2007 John Wiley \& Sons, Ltd.

}, doi = {10.1002/pip.799}, url = {http://dx.doi.org/10.1002/pip.799}, author = {S. P. Bremner and M. Y. Levy and Christiana B Honsberg} }