Metal Chalcohalides: Next Generation Photovoltaic Materials?

Abstract

Metal chalcohalides have recently been highlighted as so-far overlooked semiconductors that could play an important role in the future of photovoltaics (PV). Indeed, the blooming field of emergent PV technologies is still in search for stable, efficient, and environmentally-friendly light-harvesting materials to be used either in single-junction solar cells or multijunction devices in combination with silicon or another absorbers. Under the broad terms of metal chalcohalides, there exists a plethora of semiconductor materials with different chemical, structural, and optoelectronic characteristics. While some have already been implemented in solar cells with power conversion efficiencies up to 4–5%, others are only theoretically described. This perspective article offers a general overview of these materials as potential next-generation absorbers in PV and also discusses possible limitations, not only related to intrinsic materials’ properties but also to processing conditions.