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In this article, we present synthesis and spectral study of Zn(3-x)Lix(VO4)2 (x = 0, 0.01, 0.02, 0.03) samples. The orthorhombic phase of all the samples is validated by their XRD pattern. The crystallinity of Zn3(VO4)2 is improved by doping Li+ ions and is supported by the augmentation in crystallite size. The absorption band of the phosphors covers the near-UV region. The XPS analysis ascertains the V+5 oxidation state of vanadium thereby confirming the single-phase of the phosphors. The Li+ ion doping enhances the broadband excitation in the near UV region and emission band of Zn3(VO4)2 in the visible region with stokes shift of 9517.3 cm−1. The increased PL lifetime of the emission bands is observed after Li+ ion doping. The calculated activation energy of Li+ doped Zn3(VO4)2 phosphor is 0.29 eV and there is a 44% loss of emission intensity at 150 °C. Thus, with the broadband near-UV excitation and greenish-yellow emission, the Li+ doped zinc vanadate phosphor can be utilized with near-UV LED chips for the realization of white light.

Abstract: Aluminum hydroxides are considered to be a potential abundant, low‐cost blue emissive material to construct UV‐pumped white light‐emitting diodes (WLEDs). In this work, a single‐source precursor chemical vapor decomposition method is adapted to fabricate stable, strongly emissive aluminum hydroxide phosphors with photoluminescence quantum yield of up to 69% in solid state by thermal decomposing aluminum diacetate hydroxide (Al(OH)(Ac)2) at temperatures (260–360 °C) in N2 atmosphere. It exhibits layered, amorphous structure and its emission of aluminum hydroxide is enhanced by electron‐donating surface hydroxyl groups and originates from F+ centers and carbon‐related defects contributing to UV (388 nm) and blue (450–520 nm) spectral regions, respectively. Employing the as‐fabricated aluminum hydroxides as blue phosphor and CuInS2 nanocrystals as red phosphor, high color rendering and high‐efficiency WLEDs with luminous efficiencies up to 37 lm W−1 and high color rendering index of 91 are fabricated. This is the best performance reported so far for aluminum hydroxide based LEDs. [ABSTRACT FROM AUTHOR]

• The rare-earth free self-luminescent zinc vanadate phosphors are prepared via cost efficient citrate sol–gel method. • The XRD analysis confirms the improvement in crystallinity of the host phosphor with Li+ doping. • The broadband near UV excitation and the greenish-white emission of the prepared phosphor is enhanced by Li+ doping. • The high activation energy of Li+ doped Zn 3 (VO 4) 2 confirms the thermal stability of the phosphor. • The large Stokes shift for the Li+ doped phosphor of about 9517.3 cm−1 has been obtained and the CCT value for the same is 4871 K. In this article, we present synthesis and spectral study of Zn (3-x) Li x (VO 4) 2 (x = 0, 0.01, 0.02, 0.03) samples. The orthorhombic phase of all the samples is validated by their XRD pattern. The crystallinity of Zn 3 (VO 4) 2 is improved by doping Li+ ions and is supported by the augmentation in crystallite size. The absorption band of the phosphors covers the near-UV region. The XPS analysis ascertains the V+5 oxidation state of vanadium thereby confirming the single-phase of the phosphors. The Li+ ion doping enhances the broadband excitation in the near UV region and emission band of Zn 3 (VO 4) 2 in the visible region with stokes shift of 9517.3 cm−1. The increased PL lifetime of the emission bands is observed after Li+ ion doping. The calculated activation energy of Li+ doped Zn 3 (VO 4) 2 phosphor is 0.29 eV and there is a 44% loss of emission intensity at 150 °C. Thus, with the broadband near-UV excitation and greenish-yellow emission, the Li+ doped zinc vanadate phosphor can be utilized with near-UV LED chips for the realization of white light. [ABSTRACT FROM AUTHOR]

• The Bi3+ doped Zn 3 (VO 4) 2 was prepared by the facile urea assisted solution combustion process. • Authentication of the phase purity of the prepared phosphors by the XRD and FT-IR analysis. • The red-shift is observed in the absorption edge after Bi3+ doping. • The PL emission is enhanced by the factor of 11 after 1% Bi3+ doping in Zn 3 (VO 4) 2. • The prepared phosphors avoid visible light absorption, give greenish-white emission, and are cost-efficient. In this paper, we have explored the photoluminescence properties of rare-earth free Zn (3-x) Bi x (VO 4) 2 (x = 0, 0.01, 0.03, 0.05) phosphors, synthesized by solution combustion method. The Rietveld refinement confirms that the prepared phosphors have an orthorhombic phase. The Bi3+ doping in the host supports the crystallite growth and reduction of microstrain. The absorption study ascertains the shift in the absorption edge with Bi3+ doping. The lowering of Urbach energy with Bi3+ doping in the host confirms the improvement of crystallinity. The prepared phosphors have near-Ultraviolet (UV) excitation of 350 nm, which reduces visible light reabsorption. The host has broadband emission centered on 540 nm and is enhanced by the factor of 11 after 1% doping of Bi3+ ions. The emission enhancement is attributed to the improved crystallinity and reduced microstrain. Thus, Bi3+ doped Zn 3 (VO 4) 2 phosphor can be used as a greenish-white emission source for optical devices. [ABSTRACT FROM AUTHOR]