摘要： Photon upconversion enjoys an increasing interest in the last years due to its high potential for solar energy harvesting and in bio-imaging. A challenge for triplet-triplet annihilation upconversion (TTA-UC) processes is to realize these features in solid materials without undesired phase segregation and detrimental dye aggregation. To achieve this, we combine a palladium porphyrin sensitizer and a 9,10-diphenylanthracene annihilator within a crystalline mesoporous metal-organic framework using an inverted design. In this modular TTA system, the framework walls constitute the fixed sensitizer, while caprylic acid coats the channels providing a solvent-like environment for the mobile annihilator in the channel. The resulting solid material shows green-to-blue delayed upconverted emission with a luminescence lifetime of 373±5 μs, a threshold value of 329 mW cm–2 and a triplet-triplet energy transfer efficiency of 82%. The versatile design allows straightforward changing the acceptor amount and type.