Understanding experimental characterization of intermediate band solar cells

An intermediate band solar cell is a novel photovoltaic device with the potential to exceed the efficiency of single gap solar cells. In the last few years, several prototypes of these cells, based on different technologies, have been reported. Since these devices do not yet perform ideally, it is sometimes difficult to determine to what extent they operate as actual intermediate band solar cells. In this article we provide the essential guidelines to interpret conventional experimental results (current-voltage plots, quantum efficiency, etc.) associated with their characterization. A correct interpretation of these results is essential in order not to mislead the research efforts directed towards the improvement of the efficiency of these devices. © 2012 The Royal Society of Chemistry.This work has been supported by the 7th Framework European Project NGCPV (Grant number 283798). EA acknowledges a Juan de la Cierva Post-Doctoral Fellowship (JCI-2011-10639) from the Spanish Ministry of Science.Peer Reviewe