Broadband emission from Er-contained yttrium orthophosphate and orthovanadate nanopowders excited by near infrared radiation

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

“…Moreover, the 650 nm emission tended to increase in relation to the content of Er 3+ doped in LDH, which increased from 1.96 to 14.14%. The emission at ~650 nm is often found in the downconversion emission spectra of Er 3+ ‐doped compounds [ 30,31,34,55,57 ] as well as the upconversion emission spectra of RE/Er 3+ co‐doped compounds. [ 33,35,58–64 ] When samples were excited with 480, 520, and 565 nm wavelengths, some strong emissions at 720, 780, and 850 nm, respectively, occurred, but the emission at 650 nm did not emerge.…”

“…Xin [ 64 ] found three emissions at ~550, ~660, and 845 nm in the upconverted emission spectra of the TiO 2 ‐Yb 2 O 3 :Er,Li complex nucleoproteins (NPs) irradiated using a 980 nm diode laser, and the emission at 845 nm was ascribed to the 4 F 9/2 → 4 I 9/2 transition. Khrushchalina and colleagues [ 31 ] observed some weak emissions at about 540, 660, and 800 nm in Y (1‐ x ) Er x PO 4 and Y (1‐ x ) Er x VO 4 under 1550 nm and 970 nm exaction, and the 800 nm was assigned to the 4 I 9/2 → 4 I 15/2 transition. Xia and colleagues [ 65 ] found emissions at 673 and 800 nm in upconverted emission spectra of Yb/Er/Tm: Na 3 ZrF 7 NCs under 980 nm laser excitation, and the emission at 800 nm was attributed to the 3 H 4 → 3 H 6 and 2‐photon processes.…”

“…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.…”

Blackbody emission from CaF2and ZrO2nanosized dielectric particles doped with Er3+ions

“…A vivid example is the appearance of broadband "white" emission (BBWE) in nanoscale dielectric materials when they are excited by intense laser radiation. [1][2][3][4][5][6][7][8][9][10][11][12][13][14] In most cases, this emission was observed in compounds doped with rare-earth (RE) ions upon excitation into the absorption band of these ions. An analysis of these publications indicates that there are different points of view on the nature of the observed phenomenon and the processes responsible for it.…”