The envisaged design and developme nt of individual mate rials to excavate a broader spectrum of desired properties and offer multiple applications are highly necessitating.Keeping this in mind,a series of forsterite-...The envisaged design and developme nt of individual mate rials to excavate a broader spectrum of desired properties and offer multiple applications are highly necessitating.Keeping this in mind,a series of forsterite-structured Mg_(2)GeO_(4):Eu^(3+)(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 Puma 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 Mg_(2)GeO_(4):Eu^(3+)(1 mol%-9 mol%)nanophosphors was estimated and obtained to be~4.12-4.32 eV.The photoluminescence emission spectra exhibit intense peaks at^(5)79,589,610,661,and 707 nm,which are due to characteristic^(5)D_(0)→^(7)F_(0),^(5)D_(0)→^(7)F_(1),^(5)Do→^(7)F_(2),^(5)D_(0)→^(7)F_(3)and^(5)D_(0)→^(7)F_(4)transitions of Eu^(3+)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 ofγ-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 Mg_(2)GeO_(4):Eu^(3+)(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.展开更多
Nanomaterials have emerged as an active area of research.This is because of their broad spectrum of applications such as sensors,white light emitting diodes(LEDs),electronic displays,and other optoelectronic devices i...Nanomaterials have emerged as an active area of research.This is because of their broad spectrum of applications such as sensors,white light emitting diodes(LEDs),electronic displays,and other optoelectronic devices in the optics and electronic industries owing to their size-and shape-dependent properties.The synthesis technique plays a crucial role in tuning the size and shape of the materials.Herein,we briefly describe these nanomaterials'fundamental aspects,properties,and applications.Various nanomaterial synthesis methods are discussed.Their advantages and disadvantages are highlighted in conjunction with the criteria for selecting a synthesis method.The principle underlying the sonochemical method and its applicability in synthesizing diverse sub-15 nm size nanoparticles(NPs)are presented.The main objective of this article is to review recent studies on lanthanide-doped nanophosphors and the various parameters that play key roles in achieving optimum luminescence emission.Both down-conversion and up-conversion mechanisms are discussed.The importance of the combinations and concentrations of the synthesizer/activator,color tuning,and host material are emphasized.展开更多
基金Project supported by the Department of Science&Technology(DST)(Science and Engineering Research Board(SERB)-Core Research Grant(CRG))Government of India(CRG/2020/006446)。
文摘The envisaged design and developme nt of individual mate rials to excavate a broader spectrum of desired properties and offer multiple applications are highly necessitating.Keeping this in mind,a series of forsterite-structured Mg_(2)GeO_(4):Eu^(3+)(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 Puma 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 Mg_(2)GeO_(4):Eu^(3+)(1 mol%-9 mol%)nanophosphors was estimated and obtained to be~4.12-4.32 eV.The photoluminescence emission spectra exhibit intense peaks at^(5)79,589,610,661,and 707 nm,which are due to characteristic^(5)D_(0)→^(7)F_(0),^(5)D_(0)→^(7)F_(1),^(5)Do→^(7)F_(2),^(5)D_(0)→^(7)F_(3)and^(5)D_(0)→^(7)F_(4)transitions of Eu^(3+)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 ofγ-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 Mg_(2)GeO_(4):Eu^(3+)(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.
文摘Nanomaterials have emerged as an active area of research.This is because of their broad spectrum of applications such as sensors,white light emitting diodes(LEDs),electronic displays,and other optoelectronic devices in the optics and electronic industries owing to their size-and shape-dependent properties.The synthesis technique plays a crucial role in tuning the size and shape of the materials.Herein,we briefly describe these nanomaterials'fundamental aspects,properties,and applications.Various nanomaterial synthesis methods are discussed.Their advantages and disadvantages are highlighted in conjunction with the criteria for selecting a synthesis method.The principle underlying the sonochemical method and its applicability in synthesizing diverse sub-15 nm size nanoparticles(NPs)are presented.The main objective of this article is to review recent studies on lanthanide-doped nanophosphors and the various parameters that play key roles in achieving optimum luminescence emission.Both down-conversion and up-conversion mechanisms are discussed.The importance of the combinations and concentrations of the synthesizer/activator,color tuning,and host material are emphasized.
