Congratulations to Dave, Bernard, and Andrew for publishing their paper “Detailed balance analysis of the conversion efficiency of nanocrystal quantum dot solar cells” in the Journal of Applied Physics
The paper details our theoretical calculations of the detailed balance conversion efficiency limits of nanocrystal solar cells with excitonic absorption profiles.
Intensive research efforts world-wide are currently directed towards the development of next-generation photovoltaic technologies that combine high conversion efficiency and low cost. Much of this research is focused on novel absorber materials. Among the various materials under investigation, nanocrystal quantum dots have garnered increasing attention and their potential has been underscored in steady advances in the conversion efficiency of prototype solar cells. A unique aspect of nanocrystal absorbers is their size-tunable absorption profiles; this aspect has already been exploited in prototype devices such as single junction and tandem solar cells.
The excitonic absorption profile also has important implications on the conversion efficiency limit of nanocrystal solar cells, which have, to the best of our knowledge, not been previously considered. Our calculations illustrate the fundamental relationship between the shape of the nanocrystal absorption profile and the conversion efficiency. We determined conversion efficiency limits as a function of exciton peak and width. Importantly, our results illustrate that photovoltaic conversion efficiency in nanocrystal solar cells requires careful consideration of the excitonic peak width: peak width relates directly to generated current density, but inversely to open circuit voltage. We extend our calculations to show the conversion efficiency limits for nanocrystal solar cells with multiexciton generation and conversion efficiency limits in tandem nanocrystal solar cells.