Blue organic long-persistent luminescence via upconversion from charge-transfer to locally excited singlet state.

ABSTRACT: Long-persistent luminescence (LPL) materials have applications from safety signage to bioimaging; however, existing organic LPL (OLPL) systems do not align with human scotopic vision, which is sensitive to blue light. We present a strategy to blueshift the emissions in binary OLPL systems by upconverting the charge-transfer (CT) to a locally excited (LE) singlet state. Through rigorous steady-state and time-resolved photoluminescence spectroscopy and wavelength-resolved thermoluminescence measurements, we provide the direct experimental evidence for this upconversion in OLPL systems featuring small energy offsets between the lowest-energy CT and LE singlet states. These systems exhibited strong room temperature LPL, particularly when extrinsic electron traps are added. Importantly, the dev

SUBMITTER: Lin Z 

PROVIDER: S-EPMC11920369 | biostudies-literature | 2025 Mar

REPOSITORIES: biostudies-literature