Exploring one material for dual applications: A red-emitting Mg2GeO4:Eu3+ nanophosphor for future generation energy efficient WLEDs and dosimetric applications

Abstract

The envisaged design and development of individual materials to excavate a broader spectrum of desired properties and offer multiple applications are highly necessitating. Keeping this in mind, a series of forsterite-structured Mg2GeO4:Eu3+ (1 mol%–9 mol%) nanophosphors was synthesized via a solution combustion method using oxalyl dihydrazide as a fuel. The X-ray diffraction patterns confirm the orthorhombic crystal system with a Pnma space group. Morphological results clearly show irregularly shaped cluster-like structures with aggregation of the particles. Employing diffuse reflectance spectra, the optical energy band gap of the Mg2GeO4:Eu3+ (1 mol%–9 mol%) nanophosphors was estimated and obtained to be ∼4.12–4.32 eV. The photoluminescence emission spectra exhibit intense peaks at ∼579, 589, 610, 661, and 707 nm, which are due to characteristic 5D0 → 7F0, 5D0 → 7F1, 5D0 → 7F2, 5D0 → 7F3 and 5D0 → 7F4 transitions of Eu3+ ions, respectively. The Commission International de L'Eclairage color coordinates are gradually tuned from pale red (0.5980, 0.4012) to a pure red (0.6385, 0.3611) region. Thermoluminescence glow peaks showcase excellent super -linear response at low doses of γ-irradiations, indicating that the prepared phosphor can be used in thermoluminescent personal dosimetry which is a biological tissue equivalent. The aforementioned results demonstrate that the prepared Mg2GeO4:Eu3+ (1 mol%–9 mol%) nanophosphors are considered an excellent candidate for dual applications, i.e., red component in future generation white-light-emitting diodes (WLEDs) and personal dosimetric applications.