Triplet-Triplet Annihilation Upconversion in a MOF with Acceptor-Filled Channels.

ABSTRACT: Photon upconversion has enjoyed increased interest in the last years due to its high potential for solar-energy harvesting and bioimaging. 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 solventlike environment for the mobile annihilator in the channels. The resulting solid material shows green-to-blue delayed upconverted emission with a luminescence lifetime of 373±5??s, a threshold value of 329?mW?cm-2 and a triplet-triplet energy transfer efficiency of 82?%. The versatile design allows straightforward changing of the acceptor amount and type.

SUBMITTER: Gharaati S 

PROVIDER: S-EPMC7027809 | biostudies-literature | 2020 Jan

REPOSITORIES: biostudies-literature