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

中文翻译：

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大块金属卤化物钙钛矿作为三重敏化剂：负责上转换

通过三重态-三重态湮灭的光子上转换有可能提高光伏的性能，因为可以利用额外的子带隙光子。最近，块状金属卤化物钙钛矿材料已被引入作为三线态敏化剂，当与三线态湮灭剂红荧烯耦合时，导致近红外到可见光的上转换。也许最令人兴奋的是，钙钛矿层可以吸收高达 60% 的波长高达 780 nm 的入射光，这是之前研究过的 PbS 纳米晶敏化剂无法实现的壮举。然而，被认为是通过自由电荷机制发生的三重态敏化过程的确切性质尚未完全阐明，这在很大程度上是由于这种上转换系统的复杂性。钙钛矿敏化上转换系统，虽然仍处于起步阶段，