Adam D Alfieri, Deep Jariwala
Elemental selenium (Se), tellurium (Te), and their alloys (TexSe1-x) have re-emerged over the past decade as a promising materials system for low-cost and sustainable thin-film optoelectronic devices. In particular, Se has become a promising material for wide bandgap photovoltaics (PVs), and TexSe1-x has arisen as a high-performance thin-film option for infrared (IR) photodetectors. In this review, we focus on recent developments in Se PVs and TexSe1-x short-wave IR (SWIR) photodiodes (PDs). We discuss the motivations for pursuing these materials, the fundamental properties, considerations for toxicity and sustainability, and the advances in materials science and device engineering. Finally, we discuss open challenges and underexplored opportunities for further development.