Abstract: Conventional photoluminescence (PL) yields at most one emitted photon for each absorption event. Downconversion (or quantum cutting) materials can yield more than one photon by virtue of energy transfer processes between luminescent centers. In this work, we introduce Gd2O2S:Tm31 as a multi-photon quantum cutter. It can convert near-infrared, visible, or ultraviolet photons into two, three, or four infrared photons of ,1800 nm, respectively. The cross-relaxation steps between Tm31 ions that lead to quantum cutting are identified from (time-resolved) PL as a function of the Tm31 concentration in the crystal. A model is presented that reproduces the way in which the Tm31 concentration affects both the relative intensities of the various emission lines and the excited state dynamics and providing insight in the quantum cutting efficiency. Finally, we discuss the potential application of Gd2O2S:Tm31 for spectral conversion to improve the efficiency of next-generation photovoltaics.

Autoría

Descargar referencia