Modification of photoluminescence wavelength and decay constant of Cr:Gd₃Ga₅O₁₂ substituted by Ca/Si cation pair

Abstract

In this study, the photoluminescence wavelength and decay constant of Cr:Gd₃Ga₅O₁₂ garnet oxide were modified by substituting Gd³⁺/Ga³⁺ cations with a Ca²⁺/Si⁴⁺ cation pair. The primary objective of this study was to shift the emission wavelength to the near-infrared (NIR) region and accelerate decay of Cr:Gd₃Ga₅O₁₂ for its potential use as a scintillation detector in medical applications. The incorporation of Ca²⁺ and Si⁴⁺ ions in site of Gd³⁺/Ga³⁺ ions resulted in a significant redshift in the photoluminescence wavelength of Cr³⁺ ions and an acceleration of decay. The results clearly demonstrated that Ca²⁺/Si⁴⁺ cation pair substitution is a clearly effective strategy for modulating the optical properties of Cr:Gd₃Ga₅O₁₂, with the potential to develop a NIR garnet scintillator.