Ultrahigh-sensitive optical temperature sensing based on quasi-thermalized green emissions from Er:ZnO

Abstract

Fluorescence intensity ratio (FIR) based optical temperature sensors employ the variation of intensity ratio between two peaks, which are very close to each other. Here, we prepare Er doped ZnO microrods by a hydrothermal route and exploit them for FIR based temperature sensing. The Er:ZnO shows the band-to-band UV emission and broad defect emissions with small Er related peaks upon excitation with a 355 nm laser, while only peaks corresponding to Er transitions are observed with 532 nm laser excitation. The green emissions (H → I, S → I) under 532 nm excitation are considered for temperature sensing performance as they possess a quasi-thermal equilibrium between them and the variation of intensity ratio with temperature follows a Boltzmann type distribution. The sensitivity obtained here is very high (3445/T K) compared to the reported Er ion based temperature sensors and can be applied in a wide range of temperature (83-493 K). The value of sensitivity is found to be almost independent of the concentration of Er doping and is the highest reported for Er-doped materials.

Reduced graphene oxide-based broad band photodetector and temperature sensor: effect of gas adsorption on optoelectrical properties

“…We have also tried to fit the I-V characteristics with other transport mechanisms such as Poole- This equation is similar to the expression for relative sensitivity in fluorescence intensity ratio based optical temperature sensors (Senapati and Nanda, 2017). TCR values have been plotted in figure 3d and it varies from -3.5*10 -2 °C -1 and -7.4*10 -3 °C -1 in 140 K to 318 K temperature range.…”

Optical thermometry based on thermal population of low-lying levels of Eu3+ in Ca2.94Eu0.04Sc2Si3O12

“…Temperature-dependent luminescence properties of materials based on rare earth elements have been widely studied for their applications in non-contact optical thermometry. [1][2][3][4] Many of these investigations have focused on the uorescence intensity ratio (FIR) of two thermally coupled excited energy levels (TCEELs) of rare earth ions such as Pr 3+ , 5 Nd 3+ , 6,7 Gd 3+ , 8 Dy 3+ , 9,10 Ho 3+ , 11,12 Er 3+ , [13][14][15][16][17][18] and Tm 3+ , 19 and have frequently involved upconversion (UC) luminescence. 6,8,[11][12][13][14][15][16]19 In particular, the FIR technique based on TCEELs has the advantage of requiring few measurements since it is not susceptible to uctuations of excitation power.…”

MgO Nanocubes as Self-Calibrating Optical Probes for Efficient Ratiometric Detection of Picric Acid in the Solid State

“…The O 1s high-resolution XPS spectra are deconvoluted into various Gaussian peaks as given in Figure d,e for MgO-600 and MgO-1200, respectively. For MgO-600, various peaks are observed at 529.2, 531, 533.3, and 535.4 eV, and the O-1s peaks at 529.4, 531.2, and 532.6 eV are observed for MgO-1200. − The low-energy peaks correspond to the Mg–O bonding, and all other higher energy peaks corresponds to the defect O species and adsorbed oxygen or other oxygen content corresponds to OH-radicals, among others. − Figure f shows the DRS data of the as-prepared MgO nanocubes. The spectra show the reflectance values obtained for all the samples in the 200–1000 nm wavelength range with different absorbance spikes in various regions.…”