Strong visible up-conversion emissions and thermometric applications of Er3+–Yb3+ codoped Al2O3 prepared by the sol–gel method

Abstract

at the sintering temperature of 1,273 K. By a 978 nm semiconductor laser diodes excitation, the visible up-conversion emissions centered at about 523, 545, and 660 nm were obtained. The temperature dependence of the green up-conversion emissions was studied over a wide temperature range of 300-825 K, and the reasonable agreement between the calculated temperature by the fluorescence intensity ratio (FIR) theory and the measured temperature proved that Er 3+ -Yb 3+ codoped Al 2 O 3 plays an important role in the application of high temperature sensor.

Photon upconverting nanoparticles for luminescent sensing of temperature

“…13 Dong et al achieved a temperature resolution of 0.3 C by using Al 2 O 3 as the host material and Er 3+ and Yb 3+ as dopants. 28,29 Nanoparticles consisting of Gd 2 O 3 doped with Er 3+ and Yb 3+ were employed by Singh et al 16 Alencar et al 24 investigated Er 3+ doped BaTiO 3 nanocrystals regarding their temperature dependency of the upconversion emission.…”

Temperature Sensing with Up-Converting Submicron-Sized LiNbO3:Er3+/Yb3+Particles

“…[2][3][4][5][6][7][8][9][10][11] Additionally, in materials co-doped with Yb 3þ ions, Er 3þ can be excited by taking advantage of the high absorption cross section of Yb 3þ ions at 980 nm and the efficient energy transfer up-conversion processes that populate the greenemitting levels. [11][12][13][14][15][16][17][18][19][20] This excitation scheme is particularly useful for biological applications, due to the absence of autofluorescence in biological tissues at that wavelength. [21][22][23] More recently, the interest has been readdressed to microand nano-sized materials that can be used as temperature sensors in many systems where other methods are unpractical, such as microelectronic circuits, biological tissues and inside cells.…”

Strong up-conversion emissions in ZnO:Er3+, ZnO:Er3+–Yb3+ nanoparticles and their surface modified counterparts

“…The possible explanation is as follows. On one hand, the cross-section of Er 3+ under 980 nm laser excitation is very low [30] and on the other hand, there are no energy feeders such as Yb 3+ to transfer energy to Er 3+ ions through ET process. Hence, at any time only a little part of Er 3+ ions are at the excited states, not to mention the ESA process.…”