UV emission of Gd³⁺ in the presence of Cu²⁺: Towards luminescence quenching through quantum cutting?

Abstract The first investigation into the ultraviolet (UV) photoluminescence of gadolinium(III) in the presence of copper(II) is reported. A melt-quenched barium phosphate glass was used as a model matrix. The optical spectroscopy assessment shows that with increasing CuO concentration the Cu²⁺ absorption band grows steadily, whereas the UV emission from Gd³⁺ ions is progressively quenched. The data, thus, suggests the existence of a Gd³⁺→Cu²⁺ energy-transfer process ocurring through quantum cutting. A downconversion/cross-relaxation pathway proceeding through a virtual state in Gd³⁺ is proposed. These findings suggest gadolinium(III) could potentially be used in the optical sensing of copper(II). A quantum cut above: Photoluminescence quenching of Gd³⁺ ions in the presence of Cu²⁺ impurities in glass is demonstrated. The phenomenon of quantum cutting is proposed to be involved in the energy transfer between Gd³⁺ and Cu²⁺ ions. The findings suggest the potential of gadolinium(III) for optical sensing of copper(II), which could be explored for analytical applications.