Cooperative quantum cutting in one-dimensional (YbxGd1−x)Al3(BO3)4:Tb3+ nanorods

Abstract

Near-infrared (NIR) quantum cutting (QC) involving the emission of two NIR photons per absorbed photon via a cooperative downconversion mechanism in one-dimensional (1D) $\left({\mathrm{Yb}}_x{\mathrm{Gd}}_{1-x}\right){\mathrm{Al}}_3{\left(\mathrm{B}{\mathrm{O}}_3\right)}_4:{\mathrm{Tb}}^{3+}$ nanorods has been demonstrated. The authors have analyzed the measured luminescence spectra and decay lifetimes and proposed a mechanism to rationalize the QC effect. Upon excitation of ${\mathrm{Tb}}^{3+}$ with a blue-visible photon at $485\mathrm{nm}$ , two NIR photons could be emitted by ${\mathrm{Yb}}^{3+}$ through an efficient cooperative energy transfer from ${\mathrm{Tb}}^{3+}$ to two ${\mathrm{Yb}}^{3+}$ with optimal quantum efficiency as great as 196%. The development of 1D ${\mathrm{Tb}}^{3+}–{\mathrm{Yb}}^{3+}$ QC nanomaterials could open up a possibility to realize high efficiency silicon-based solar cells by means of downconversion of the green-to-ultraviolet part of the solar spectrum to $\sim 1000\mathrm{nm}$ photons with a twofold increase in the photon number.