Tellurene Polymorphs: A New Frontier for Solar Harvesting with Strong Exciton Anisotropy and High Optical Absorbance

Abstract By using ab initio simulations based on density functional theory and many‐body perturbation theory, a comprehensive analysis of the distinct optical signatures of various tellurene polymorphs and their associated unique anisotropic excitonic characteristics is presented. Despite the atomic thickness of these materials, these findings reveal that their optical absorbance reaches as high as 50% in the near‐infrared and visible range. This investigation highlights the exceptional potential of these 2D semiconducting materials in the development of ultra‐thin and flexible homo‐ and hetero‐junctions for solar light harvesting, achieving photoconversion efficiencies up to 19%, a performance level comparable to current silicon technologies.