Discovery of high-performance materials
remains one of
the most
active areas in photovoltaics (PV) research. Indirect band gap materials
form the largest part of the semiconductor chemical space, but predicting
their suitability for PV applications from first-principles calculations
remains challenging. Here, we propose a computationally efficient
method to account for phonon-assisted absorption across the indirect
band gap and use it to screen 127 experimentally known binary semiconductors
for their potential as thin-film PV absorbers. Using screening descriptors
for absorption, carrier transport, and nonradiative recombination,
we identify 28 potential candidate materials. The list, which contains
20 indirect band gap semiconductors, comprises well-established (3),
emerging (16), and previously unexplored (9) absorber materials. Most
of the new compounds are anion-rich chalcogenides (TiS3 and Ga2Te5) and phosphides (PdP2, CdP4, MgP4, and BaP3) containing
homoelemental bonds and represent a new frontier in PV materials research.
Our work highlights the previously underexplored potential of indirect
band gap materials for optoelectronic thin-film technologies.