Broadband Ce(III)-Sensitized Quantum Cutting in Core-Shell Nanoparticles: Mechanistic Investigation and Photovoltaic Application.

Quantum cutting in lanthanide-doped luminescent materials is promising for applications such as solar cells, mercury-free lamps, and plasma panel displays because of the ability to emit multiple photons for each absorbed higher-energy photon. Herein, a broadband Ce-sensitized quantum cutting process in Nd ions is reported though gadolinium sublattice-mediated energy migration in a NaGdF:Ce@NaGdF:Nd@NaYF nanostructure. The Nd ions show downconversion of one ultraviolet photon through two successive energy transitions, resulting in one visible photon and one near-infrared (NIR) photon. A class of NaGdF:Ce@NaGdF:Nd/Yb@NaYF nanoparticles is further developed to expand the spectrum of quantum cutting in the NIR. When the quantum cutting nanoparticles are incorporated into a hybrid crystalline silicon (c-Si) solar cell, a 1.2-fold increase in short-circuit current and a 1.4-fold increase in power conversion efficiency is demonstrated under short-wavelength ultraviolet irradiation. These insights should enhance our ability to control and utilize spectral downconversion with lanthanide ions.