Synthesis and characterization of a CsPbCl₃ perovskite doped with Nd³⁺: structural, optical, and energy transfer properties

The purpose of this paper is to synthesize a micrometric inorganic perovskite CsPbCl3:Nd3+ and investigate the impact of doping with rare-earth ions on structural and optical properties, as well as energy transfer pathways between the host and dopant. Herein, we report the solid-state reaction synthesis of a concentration series of CsPbCl3:x%Nd3+ annealed under a nitrogen atmosphere. Additional doping of a material that already exhibits luminescence with an optically active ion increases its application potential. Structural features were determined using X-ray powder diffraction and Raman spectroscopy. Morphology studies performed with scanning electron microscopy revealed micrometric, well-separated cubic-like crystallites with a good distribution of individual elements. Surprisingly, a photoluminescence (PL) study showed that only blue emission appears when the material is excited with a diode operating in the UV range. Apparently, the emission of Nd3+ ions can only be obtained with direct excitation of the lanthanide. The photoluminescence excitation (PLE) spectrum monitored for Nd3+ emission confirmed the lack of energy transfer between the host and dopant. Possible explanations for this behavior have been put forth and substantiated by the first-principles electronic structure calculations in the framework of hybrid density functional theory.