SYNTHESIS AND INVESTIGATION OF LuAG:Pr,B COATINGS ON QUARTZ SUBSTRATE OBTAINED BY SOL-GEL SPIN COATING TECHNIQUE

Greta Inkrataitė1, Ramūnas Skaudžius1

1 Institute of Chemistry, Faculty of Chemistry and Geosciences, Vilnius University, Vilnius, Lithuania

[email protected]

In recent years materials with luminescent properties have become very popular. In addition, these materials are very popular for usage in lamps and other light emitting devices, but nowadays scintillators and their research is becoming a very interesting subject for scientists. Scintillators are the basis for devices, that are used for radioactive contamination detection and measurement, nuclear material monitoring, also they are included in the computer detector composition of the tomography devices. There are various compounds that can be used as scintillators, but one of the most popular are those which have a garnet structure [1]. Amongst others, these can be yttrium or lutetium aluminum garnet, doped with different lanthanides (YAG:Ln; LuAG:Ln). These inorganics compounds have the required optical properties and radiation resistance [2]. The development of new scintillators is important. However, not the materials which are used are important but also their form. The preparation of powder is the simplest, but they are not suitable for the construction of scintillator detectors. Best suited and used for the manufacture of various devices are single crystals. In addition to single crystals, coatings on various pallets or microfibers can be used [3]. Due to the possibility of using different substrates, different methods of coating, materials with different properties can be prepared, which makes this method widely used. Using the sol-gel method we can obtain homogeneous multicomponent coatings at low temperature, leaving the possibility of synthesizing compounds with emission intensity [4].

Improvement of luminescence is essential for getting the fastest scintillators properties. One way to do this is to additionally dope compounds with other elements. Replacing one element with another in the crystal lattice can influence the properties of the materials. The most common goal is to improve key parameters: compound emission intensity, quantum efficiency and decay times. One of the greatest scintillators drawbacks that is being addressed is that decay time is too long. When it is extremely long, then these second signal captured by the materials overlaps with the first, making the results unreliable and provides less data than it could. Scintillators such as and LuAG:Pr doped with boron can solve this problem. If a quick quench of decay time was obtained given result would be more accurate, and this method of synthesizing scintillators could be practically applicable [5, 6].

In this work praseodymium and boron doped LuAG are synthesized on quartz substrates using sol-gel spin coating method. Boron is expected to improve required luminescent properties, and with the sol-gel method, homogeneous compounds will be synthesized at low temperatures. Phosphor coatings were analyzed by x-ray diffraction (XRD) and scanning electron microscopy (SEM). Of course, emission, excitation spectra and decay times have been investigated as well.


[1] D. S. McGregor, Materials for Gamma-Ray Spectrometers: Inorganic Scintillators, Annual Review of Materials Research, 48, 254-277 (2018).

[2] A.D. Sontakke, J. Ueda, J. Xu, et. al., A Comparison on Ce3+ Luminescence in Borate Glass and YAG Ceramic: Understanding the Role of Host's Characteristics, The Journal of Physical Chemistry C, 120, 31, 17683–17691 (2016).

[3] S. Rawat, M. Tyagi, P. K. Netrakanti, et. al., Pulse shape discrimination properties of Gd3Ga3Al2O12:Ce,B single crystal in comparison with CsI:Tl, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 840, 186–191 (2016).

[4] A. Potdevin, G. Chadeyron, D. Boyer, et. al., Sol-gel based YAG: Tb3+ or Eu3+ phosphors for application in lighting sources, Journal Of Physics D: Applied Physics, 3251–3260 (2005).

[5] C. Foster, Y. Wu, M. Koschan, et. al., Boron Codoping of Czochralski Grown Lutetium Aluminum Garnet and the Effect on Scintillation Properties, Journal of Crystal Growth, 486, 126 – 129 (2018).

[6] H. S. Yoo, W. B. Im, J. H. Kang, D. Y. Jeon, Preparation and photoluminescence properties of YAl3(BO3)4:Tb3+, Bi3+ phosphor under VUV/UV excitation Optical Materials, 31, 2, 131 – 135 (2008).