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

Abstract

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.

Structural and luminescent studies of erbium‐doped CaZrO3 green‐emitting nanophosphors

“…Figure shows FE‐SEM–EDS images of the samples with 0.5, 1.0 and 1.5 wt% Er‐doped CaZrO 3 . All the powdered samples were irregular in shape and had an agglomerate nature . The spectra clearly reveal that no impurities other than Ca, O, Zr and Er species were present in the sample.…”

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

“…To understanding the origins of strong emissions at 720, 780, and 850 nm, the energy transfer diagram of Er 3+ doped into MgAl‐LDH‐ n ( n = 1, 2, 3, 4) is described (seen in Figure 9 and based on relevant references [ 30–35,38,42,55,58–61,67 ] and the relationship between the wavelength and energy is as follows: Electrons at ground state level ( 4 I 15/2 ) can absorb energy and jump to all high energy levels and convert to excited state electrons, while Er 3+ ‐doped Mg n Al‐LDH‐n ( n = 1, 2, 3, 4) were excited by the 220 nm wavelength (5.64 eV). When the excited state electrons come back to the ground state, some excited state electrons may release energy by nonradiative transition, and some excited state electrons at 4 F 9/2 energy level may release energy by radiative transition, resulting in the 650 nm emission.…”

“…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.…”

Influence of lattice strain on Er3+ ions activated magnesium zirconium phosphate phosphors: Morphological, structural, and photoluminescence properties

“…These vibration modes are not found in the undoped MgZr 4 (PO 4 ) 6 . Moreover, the splitting of the Raman vibration band ranging from 760 to 1300 cm − 1 [vibrational peaks at 846, 991, 1079, and 1165 cm − 1 ] can be assigned to Er 3+ ions photoluminescence emission stark levels under 514.5 nm laser excitation [38][39][40][41][42]. The (PO 4 ) 3phonon energy is suppressed by Er 3+ ions photoluminescence peaks due to their domination in photoluminescence intensity.…”