Bulk Metal Halide Perovskites as Triplet Sensitizers: Taking Charge of Upconversion

Photon upconversion via triplet–triplet annihilation has the potential to improve performance of photovoltaics, as additional sub-bandgap photons can be harnessed. Recently, bulk metal halide perovskite materials have been introduced triplet sensitizers, resulting in near-infrared-to-visible when coupled annihilator rubrene. Perhaps most excitingly, layer absorb up 60% incident light at wavelengths 780 nm, a feat not possible with previously examined PbS nanocrystalline sensitizers. However, exact nature sensitization process, which is thought occur through free charge mechanism, completely elucidated, large part due complexity this system. Perovskite-sensitized systems, while still their infancy, revolutionize field photon upconversion, eventually industrial relevance, once rich photophysics system are fully understood.