Near-infrared quantum-cutting and long-persistent phosphor Ca3Ga2Ge3O12: Pr3+, Yb3+ for application in &ITin vivo&IT bioimaging and dye-sensitized solar cells

Either quantum-cutting luminescence (QCL) or long-persistent luminescence (LPL) phosphor has been attracted attention for practical applications. Due to the real-time excitation source (low efficiency) for the QCL (LPL) process, both QCL and LPL have their own shortcomings. By combining the inherent properties of QCL and LPL, we devise a concept of QCLPL (quantum cutting long persistent luminescence), which can obtain high efficient LPL (at least > 100%). Germinate Ca3Ga2Ge3O12 (CGG) is chosen as matrix due to its low phonon frequency. Pr3+ is selected as donor (D) ion owing to its ladder-like arranged energy levels which facilitate the photon absorption and subsequent energy transfer (ET). Yb3+ ion is codoped as acceptor (A) ion due to its absorption and emission in near-infrared (NIR) region. Since the "optical transmission window" of biological tissues within 700-1100 nm allows for deeper light penetration, the QCLPL CGG: Pr3-, Yb3- (CGGPY) results in increasing bioimage contrast. Meanwhile, as a down-conversion luminescent medium, CGGPY transfers UV light to NIR light, which increases the solar light harvest and photocurrent of dye-sensitized solar cells (DSSCs). Altogether, the strategy of combination of QCL and LPL processes in one host lattice has important implications for infrared lighting, DSSCs, bioimaging and et al. (C) 2017 Elsevier B.V. All rights reserved.