Ultra-small PbS nanocrystals as sensitizers for red-to-blue triplet-fusion upconversion.

ABSTRACT: Photon upconversion is a strategy to generate high-energy excitations from low-energy photon input, enabling advanced architectures for imaging and photochemistry. Here, we show that ultra-small PbS nanocrystals can sensitize red-to-blue triplet-fusion upconversion with a large anti-Stokes shift (ΔE = 1.04 eV), and achieve max-efficiency upconversion at near-solar fluences (I _th = 220 mW cm^-2) despite endothermic triplet sensitization. This system facilitates the photo-initiated polymerization of methyl methacrylate using only long-wavelength light (λ _exc: 637 nm); a demonstration of nanocrystal-sensitized upconversion photochemistry. Time-resolved spectroscopy and kinetic modelling clarify key loss channels, highlighting the benefit of

SUBMITTER: Imperiale CJ 

PROVIDER: S-EPMC8565365 | biostudies-literature | 2021 Nov

REPOSITORIES: biostudies-literature