  I propose a general quantitative framework to evaluate the quality, track the
historical development, and guide future optimization of photovoltaic (PV)
absorbers at any development level, including both experimentally synthesized
and computer-simulated materials. The framework is based on a PV figure of
merit designed to include efficiency limitations due to imperfect photocarrier
collection that are not included in classic detailed balance methods.
Figure-of-merit-driven efficiency limits including collection losses are
calculated for 28 experimentally synthesized PV absorbers and 9 PV absorbers
simulated by electronic structure methods. Among emerging absorbers for which
no working solar cells have yet been reported, there are very large differences
in their likelihood to achieve high PV efficiencies.
