Atomistic Perspective on the Intrinsic White-Light Photoluminescence of Rare-Earth Free MgMoO₄ Nanoparticles

Abstract

Intrinsic white-light photoluminescent rare-earth free materials are promising candidates in the field of environment-friendly optical devices. They are important because whitelight materials such as LED devices contribute to safe-energy from photoluminescent emission, which simulates daylight in brightness and comfort at home and/or within industrial environments. Thus, it is a natural path that experimental and theoretical efforts can be combined to understand the best way to reach superior photoluminescent properties in materials. The ultrasonic spray pyrolysis method was employed in this study to synthesize shapeoriented MgMoO 4 nanoparticles with different morphologies after heat treament, which exhibits singular photoluminescence emission spectra with intrinsic white-light emission. For a deep discussion on the electronic structure, quantum mechanical calculations at the DFT/B3LYP level were performed such as in monoclinic β-MgMoO 4 bulk in its surfaces combined with the Wulff construction. The wideband approach was considered for investigating fundamental and excited electronic states (singlet and triplet). The morphological analysis indicates a thermal-active morphological modulation that induces the stabilization of hexagonal planes such as (100) and (010). The DFT calculations enabled us to understand the charge-transfer process along [MgO 6 ] and [MoO 4 ] clusters from characterizing fundamental singlet (s) and the excited singlet (s*) and triplet (t*) electronic states.

MgMoO4 as an anode material for lithium ion batteries and its multi-electron reaction mechanism

“…The Mg atom is relatively inactive when determining the band edges of MgMoO 4 , but the occurrence of the Mg 3s and 3p states in both the valence band and conduction band indicates the role of Mg as a bridge in the coupling of tetrahedrally coordinated Mo-O electrons. Clearly, these results including the characteristics of the electronic states around the band edge and the flat top of the valence state are well consistent with Santiago et al's report 36. The electronic charge density of the VBM (Fig.2(e)) indicates charge minima oriented along the Mg-O bond directions, which is characteristic of the ionicity of the Mg-O bonds.…”

“…The XRD patterns of the MgMoO 4 power sample annealed at 650 °C are shown in Fig. 1 The lattice parameters of the sample from the refinement results and some reported in the literature are listed in Table 1, [36][37][38][39][40] and the corresponding sites and coordinates of each atom for our MgMoO 4 sample are shown in Table 2. Both the lattice parameters and corresponding atom sites and coordinates of atoms of our sample agreed with V. B. Mikhailik's report.…”

Eu2+-activated MgAl2Si4O6N4: a novel oxonitridoalumosilicate blue phosphor for white LEDs

“…Hence, it is of great research significance to explore highly efficient and thermal stable phosphors for pc-white LEDs used. 1,[5][6][7][8] Compared with other pc-white LEDs, the near-UV excited white LEDs based on the RGB tri-color phosphors have high chromaticity stability, adjustable color temperature, and high CRI, therefore they have great potential for application in fullspectrum white lighting. 9 However, blue light with a short wavelength is harmful to the human eyes.…”

“…Hence, it is of great research significance to explore highly efficient and thermal stable phosphors for pc-white LEDs used. 1,5–8…”

Experimental and Theoretical Study of Morphological and Charging Properties of Truncated Octahedron and Cubic Ceria Nanoparticles: Implications for Biomedical Applications

“…It is important to stress here that the crystal morphology could also be correlated to various material properties such as magnetism, electronic and optical properties, and so on. For example, Santiago and co-workers used a combined experimental and theoretical approach to elucidate the structural–property relationship of CuMnO 2 nanoparticles from different morphologies. − …”