Massachusetts Institute of Technology

Mark W B Wilson

Moungi G Bawendi

Vladimir Bulovic

Nicholas John Thompson

Marc A Baldo

Daniel Norbert Congreve

Mengfei Wu

Jeffrey C Grossman

Jose M Cordero

Chia-Hao Marcus Chuang

Gyuweon Hwang

Donghun Kim

The present invention generally relates to composition and methods for downconverting light. In some embodiments, the composition and methods comprise an organic material, a nanocrystal, and a ligand capable of facilitating energy transfer between the organic material and the nanocrystal. In certain embodiments, the nanocrystal has a first excited energy state with an energy less than a triplet energy state of the organic material. The organic material, in some embodiments, may be aromatic and/or include one or more pi-conjugated carbon-carbon double bonds. In some cases, incident light may be absorbed by the organic material to produce two triplet excitons. The triplet excitons may then transfer to the nanocrystal via the ligand, where they can undergo recombination, resulting in the formation low energy photons.

Compositions and methods for the downconversion of light

The size-dependent band-gap tunability and solution processability of nanocrystals (NCs) make them attractive candidates for optoelectronic applications. One factor that presently limits the device performance of NC thin films is sub-bandgap states, also referred to as trap states. Trap states can be controlled by surface treatment of the nanocrystals.

Eliminating emissive sub-bandgap states in nanocrystals

The present invention generally relates to composition and methods for upconverting light. In some embodiments, the composition and methods comprise an organic material, a nanocrystal, and a ligand capable of facilitating energy transfer between the nanocrystal and the organic material. In certain embodiments, the nanocrystal has a first excited energy state with an energy greater than a triplet state of the organic material. The organic material, in some embodiments, may be aromatic and/or include one or more pi-conjugated carbon-carbon double bonds. In some cases, incident light may be absorbed by the nanocrystal to produce triplet excitons. The triplet excitons may then transfer from the nanocrystal to the organic material and undergo triplet-triplet annihilation, creating a singlet state of approximately twice the energy of the triplet exciton. In certain embodiments, the singlet state fluoresces, resulting in the formation of a high energy photon.

Methods and compositions for the upconversion of light

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Somerville, MA, United States of America

Mark W B Wilson