Infrared and visible emissions of rare‐earth‐doped CeO 2 phosphor

In the yttrium aluminium system, the YAlO3 phosphor is a prominent host because of the yttrium aluminium ratio (1:1). Phosphor was synthesized by the solid-state reaction method at variable concentrations of erbium (0.1-2.5 mol%). This method is suitable for large-scale production and is a less time-consuming method when compared with the soft synthesis method. The prepared sample was characterized by X-ray diffraction technique and the crystallite size was calculated by Scherer's formula. Vibrational and bending analysis of prepared phosphor for optimized concentration of erbium ion is described based on the Fourier transform infrared spectroscopic technique. The photoluminescence (PL) emission spectra of prepared phosphor for variable concentrations of erbium ion were recorded and the excitation spectrum was found to be at 291 nm with three shoulder peaks at 305, 270 and 242 nm. For 291 nm excitation, the emission spectrum was found at 546 nm and 552 nm. PL intensity increased with increasing concentrations of erbium and after 2 mol% emission intensity decreased due to concentration quenching. Spectrophotometric determination of YAlO3:Er(3+) is described by CIE co-ordinates and shows an intense emission in the green region such that the prepared phosphor can act as a single host for green light emission. Thermoluminescence glow curve analysis of the YAlO3:Er(3+) phosphor was recorded for different ultraviolet (UV) light exposures and gamma exposure. Different gamma doses 0.5-2 kGy show a linear response. Kinetic parameters were calculated by the peak shape method.

“…and Table ). The peak shape method was generally called Chen's peak method which was used to determine the kinetic parameters of the glow peak of the TL materials .…”

Section: Resultsmentioning

confidence: 99%

“…The heating rate used for TL measurement was 6.7°C sec −1 . Photoluminescence emission and excitation spectrum were recorded by spectrophotofluorimetry (Shimadzu RF 5301), excitation source used was a xenon lamp .…”

Section: Methodsmentioning

confidence: 99%

Synthesis and characterization of erbium‐doped YAlO₃ phosphor

Baig¹,

Saluja²,

Dhoble

2015

“…All spectra showed the typical emission peaks of Er 3+ ions in cubic CaZrO 3 . According to the Er 3+ energy levels, the observed peaks in the green region 527–536 nm and 555–567 nm were assigned to transitions 2 H 11/2 → 4 I 15/2 and 4 S 3/2 → 4 I 15/2 of Er 3+ , respectively .…”

Section: Photoluminescence Studymentioning

confidence: 99%

“…These results indicate that the two‐photon process is responsible for green upconversion. The excited states for upconversion can be populated by several well known mechanisms: (1) excited state absorption (ESA); (2) energy transfer (ET); and (3) photon avalanche . Photon avalanche was ruled out as a possible mechanism for upconversion because no inflection point was observed in the power study.…”

Section: Photoluminescence Studymentioning

confidence: 99%

Luminescence studies and infrared emission of erbium‐doped calcium zirconate phosphor

Tiwari

Dubey

2015

The near-infrared-to-visible upconversion luminescence behaviour of Er(3+)-doped CaZrO3 phosphor is discussed in this manuscript. The phosphor was prepared by a combustion synthesis technique that is suitable for less-time-taking techniques for nanophosphors. The starting materials used for sample preparation were Ca(NO3)2.4H2O, Zr(NO3)4 and Er(NO3)2, and urea was used as a fuel. The prepared sample was characterized by X-ray diffraction (XRD). The surface morphology of prepared phosphor was determined by field emission gun scanning electron microscopy (FEGSEM). The functional group analysis was determined by Fourier transform infrared (FTIR) spectroscopy. All prepared phosphors with variable Er(3+) concentrations (0.5-2.5 mol%) were studied by photoluminescence analysis. It was found that the excitation spectra of the prepared phosphor showed a sharp excitation peak centred at 980 nm. The emission spectra with variable Er(3+) concentrations showed strong peaks in the 555 nm and 567 nm range, with a dominant peak at 555 nm due to the ((2)H(11/2),(4)S(3/2)) transition and a weaker transition at 567 nm associated with 527 nm. Spectrophotometric determination of the peak was evaluated by the Commission Internationale de I'Eclairage (CIE) method These upconverted emissions were attributed to a two-photon process. The excitation wavelength dependence of the upconverted luminescence, together with its time evolution after infrared pulsed excitation, suggested that energy transfer upconversion processes were responsible for the upconversion luminescence. The upconversion mechanisms were studied in detail through laser power dependence. Excited state absorption and energy transfer processes were discussed as possible upconversion mechanisms. The cross-relaxation process in Er(3+) was also investigated.

“…Erbium (Er 3+ )‐doped compounds have been investigated extensively over many years because of the rich energy levels in Er 3+ that result in green (530–570 nm,), red (650–700 nm), and infrared emissions (>700 nm). [ 30–39 ] These emissions are favourable for Er 3+ ‐doped compounds and their potential applications for example as lasers, amplifiers, up‐converters, sensors, and in the biomedical fields. [ 39–46 ] It is well known that the Er 3+ emissions strongly depend on their host, that is Er 3+ ions can exhibit different emissions when doped into different Er 3+ emissions.…”

Section: Introductionmentioning

confidence: 99%

New near‐infrared emissions and energy transfer in Er³⁺‐doped MgAl layered double hydroxides

Chen

Zhang

et al. 2020

A series of Er 3+-doped magnesium aluminium layered double hydroxides (Er 3+-doped, MgAl-LDHs) with different Mg 2+ /(Al 3+ +Er 3+) molar ratios were synthesized using the hydrothermal method. Compositional and structural analyses suggest that the Er 3 +-doped MgAl-LDHs kept a hexagonal structure while the Mg 2+ /(Al 3+ +Er 3+) molar ratio was at 1.0-4.1. The downconverted emission spectra of the Er 3+-doped MgAl-LDHs showed a red emission at 650 nm and strong infrared emissions at 720, 780, and 850 nm. These infrared emissions were hardly observed in previous downconverted emission spectra of Er 3+-doped materials. In the analysis of the Er 3+ energy levels and in relevant published literature, the energy transfer diagram for Er 3+-doped in MgAl-LDHs is described, and infrared emissions at 720, 780, and 850 nm may be attributed to 4 F 7/2 ! 4 I 13/2 , 2 H 11/2 ! 4 I 13/2 , and 4 S 3/2 ! 4 I 13/2 transitions of Er 3+ , respectively. Er 3+-doped MgAl-LDHs could have potential application as marking and targeting agents in the processes for drug delivery in consideration of the strong near-infrared Er 3+ emissions, as well as the special layered structure of MgAl-LDH.