Impact of Semiconductor Band Tails and Band Filling on Photovoltaic Efficiency Limits

Since the seminal work of Shockley and Queisser, assessing the detailed balance between absorbed and emitted radiative fluxes from a photovoltaic absorber has been the standard method for evaluating solar cell efficiency limits. The principle of detailed balance is one dictated by reciprocity and steady state, so that photons can be absorbed and emitted with equal probability. This basic principle has also been extended to evaluate the effects of multiple junctions, hot carriers, nanostructured geometries, multiexciton generation, subunity radiative efficiency, and many other solar cell configurations and nonidealities to estimate limiting efficiencies via modifications to the detailed balance model