Photochromism and Thermally and Optically Stimulated Luminescences of AlN Ceramic Plate for UV Sensing

Abstract

We have characterized AlN ceramic plates (SHAPAL ® , Tokuyama Corporation, Japan) for UV sensing applications. The SHAPAL ® AlN ceramic plate is a commercially available product used as a heat sink, but it shows photochromic effects and thermally and optically stimulated luminescences (TSL and OSL) after it is exposed to UV light. Upon UV exposure, a broad optical absorption band is induced in the UV-blue region (2.5-4.5 eV), and the color changes from gray to orange. A UVexposed AlN ceramic plate emits near UV light (~3.4 eV) upon thermal or optical stimulation. The TSL signal showed maximum intensity when heated to around 200 °C, whereas the OSL could be stimulated by light exposure over a wide spectral range from ~2 to 3 eV. The sensitivity of the photochromism, TSL, and OSL depended on the UV photon energy. Overall, these UV-induced effects were strongly pronounced for photon energies higher than 4.0 eV, but the photochromic effect could be seen for lower energies, though the signal was considerably smaller. The AlN ceramic plate could be used for UV sensing multiple times. The photochromic, TSL, and OSL signals could be erased by heat treatment, and the OSL signal could also be erased by exposure to low-energy light.

Photoluminescence, scintillation, and dosimetric properties of undoped and Tb-doped Ba3Gd(PO4)3 single crystals

“…The TSL glow curves were measured immediately after X-ray irradiation in order to avoid the effect of fading. The electric heater (Sakaguchi E. H Voc, SCR-SHQ-A) and Si CCD-based spectrometer (Ocean Optics, QE Pro) 32) were used to study the TSL spectra. The highest peak intensity of the TSL glow curves for each irradiation dose was used to calculate the TSL dose response functions.…”

TSL and OSL Properties of Cu-doped CaF2 Ceramics Prepared by Spark Plasma Sintering

“…Furthermore, measurements of TSL spectra were performed using a CCD-based spectrometer (QE Pro, Ocean Optics) and a temperature controller/power supply (SCR-SHQ-A, SAKAGUCHI E.H VOC) at a constant temperature. (20) In the above measurements, an X-ray generator (XRB80N100/CB, Spellman) was used as a radiation source, which was equipped with an X-ray tube with a W anode target. We used an X-ray ionization chamber (TN30013, PTW) to determine the dose during the irradiation.…”

Scintillation and dosimetric properties of LiF/CaF2:Dy eutectic composite

“…The same experimental setup is shown in Ref. 26. The TL glow curves were measured using a TL reader (TL-2000; Nanogray, Minho, Japan) by heating with a rate of 1 °C s −1 in the temperature range from 50 °C to 490 °C.…”