Thermoluminescence Studies Research Articles

Studying the thermoluminescence of limestone minerals in the vicinity of Shirpur Fort, India for dosimetric applications

Thermoluminescence (TL) is a well-established and very sensitive technique for estimating the concentration of luminescent centers in solids. Many minerals have been investigated for thermoluminescent properties to date. The present investigation deals with the thermoluminescence study of the limestone mineral. We collected the limestone mineral from the historical place Shirpur Fort at Pathri village near Vani region of Yavatmal district in Maharashtra state, India and crushed it for a few minutes to make fine powder of it. This crushed fine powdered sample is then used for further characterization. The sample was irradiated by a 60Co γ-ray irradiation source. After irradiating this sample thermoluminescence study was carried out. From the study, it was found that the TL glow curve shows a single trap located around 265°C. The study shows that this sample shows TL intensity on very high exposure. Moreover, the sample shows linearity in the TL glow curve with the exposure rate. So, this sample might be useful in high-dose dosimetric applications in TLD.

Trap‐induced persistent luminescence in organic light‐emitting diodes

AbstractLuminescence in organics that lasts for seconds to a few hours after light excitation has been reported recently, showcasing significant application potentials in flexible electronics and bioimaging. In contrast, long‐lasting luminescence that can be electrically excited, whether in organics or inorganics, is much rarer and often less efficient. In this study, we report persistent luminescence (PersL) in organic light‐emitting diodes (OLEDs) that lasts over 100 s and an energy storage effect beyond 60 min after charging with a direct‐current electric field. Thermoluminescence studies reveal that the PersL in OLEDs is induced by traps formed in a host‐guest molecular system serving as an emission layer (EML) with a trap depth of approximately 0.24 eV, consistent with the results from the same EML materials under light irradiation. Integrating results from electronic spin resonance, and density functional theory calculations, we propose a model delineating the charge carrier migration responsible for the trap‐induced PersL in OLEDs. This study on trap‐induced PersL in OLEDs may deepen our understanding of the luminescence mechanism in organic semiconductors and pave the way for expanding their applications in optoelectronics, energy storage and biological detection technologies.image

Thermoluminescence study of Nd3+ doped lanthanum tri-borate phosphor

Thermoluminescence study of Nd3+ doped lanthanum tri-borate phosphor

Study of Photoluminescence and Thermoluminescence Properties of Tb3+ Doped Green Emitting YPO4 Nanophosphors.

YPO4 nanophosphors doped with different concentrations of Tb3+ were synthesized using conventional co-precipitation method. The crystalline as well structural features were studied by using powder X-ray diffraction (PXRD) as well as Transmission electron microscope (TEM) images, which revealed highly crystalline nature of the prepared samples having particle sizes of around 40nm. EDAX spectrum also shows the elemental composition of the synthesized nanoparticles which contain Y, P, O, Tb3+as expected. Prepared samples showed emission peaks at 491, 545, 588 and 624nm under UV excitation having excitation wavelengths of 223 and 320nm. The Commission International de I'Eclairage (CIE)study shows the chromaticity co-ordinates for the 600oC annealed samples to be x = 0.239, y = 0.4 which corresponds to cool greenish light suggesting the potential applications of the prepared nanophosphor in white light emitting diodes converted from green phosphors, optical display setups and PDP applications. Thermoluminescence (TL) study was carried out after exposing the samples 5at.wt% Tb3+ doped YPO4 to gamma radiations. Kinetic parameters were calculated using Deconvolution method.

Thermoluminescence study and characterization of Mn-doped Li2B4O7 exposed to beta radiation

Thermoluminescence study and characterization of Mn-doped Li2B4O7 exposed to beta radiation

Study of Thermoluminescence and Optically Stimulated Luminescence Properties of Synthesised CaB2O4 Nanoparticles Doped with Copper.

CaB2O4 nanorods doped with different concentrations of Cu were prepared by using co-precipitation method. The recorded Thermoluminescence (TL) and Optically stimulated luminescence (OSL) of CaB2O4:Cu samples for different concentrations of Cu irradiated with 6Gy of X-Ray shows that 0.05 at.wt% of Cu concentrations have higher sensitivity. The TL and OSL kinetic parameters of glow curves were evaluated using "tgcd" and conventional fitting methods. The TL glow curve of the CaB2O4:Cu have three individual glow peaks with maximum peak temperatures at 404.50, 453.04 and 484.02K respectively. The OSL glow curves of the CaB2O4:Cu nanoparticles follow non-first order kinetics which can be fitted with the sum of two first order decay curves.

A preliminary study of phototransferred thermoluminescence of alexandrite

This study reports the phototransferred thermoluminescence (PTTL) of alexandrite. PTTL was induced by 470 nm illumination of samples beta irradiated to 150 Gy. The glow curve of its conventional TL shows five peaks, labelled as I–V. PTTL is observed at peaks I-IV. Time-response profiles of PTTL were analyzed as systems of an acceptor and donors with the number of donors determined by the preheating temperature. The attendant effect of thermal assistance and thermal quenching associated with the optically stimulated luminescence emitted during illumination of sample are reported and analyzed.

Thermoluminescence and ATR-FTIR study of UVC-irradiated low-density polyethylene (LDPE) food packaging

This research aims to study the effects of ultraviolet C (UVC) radiation on low-density polyethylene (LDPE) food packaging. Main objectives include evaluating LDPE degradation and detecting UVC radiation using thermoluminescent dosimeters (TLDs) placed under LDPE samples. Results confirm accurate UVC detection after one hour of exposure, providing a useful tool for optimize food treatment procedures.ATR-FTIR spectroscopy analysis revealed subtle alterations (<8 % transmittance relative) in UVC-irradiated LDPE samples, including possible CH breakage (2910 and 2848 cm−1) and potential CC bond vibrations (1470 cm−1), among others. However, observed variations may stem from LDPE properties rather than entirely from UVC radiation. A comparative study of UVC-induced thermoluminescence (TL) emissions provided insights into various TLDs materials. TL kinetic analysis, using computerised glow curve deconvolution (CGCD) method, unveiled trap charge activation due to UVC exposure, including partial ionization, bleaching effect and photo-transfer (PTTL) processes. LDPE samples amplified UVC-TL responses, revealing intensity differences between the TLDs attributed to the PTTL process, accentuated by the lack of an annealing treatment. Additionally, chemical composition of the TL detectors such as, type, concentration, number, oxidation states and ionic radii of their dopants may influence UVC-TL response. Consequently, TL intensity ratios follow as: GR-200 (LiF: Mg, Cu, P) > TLD-100 (LiF: Ti, Mg) > TLD-400 (CaF2: Mn) > TLD-200 (CaF2: Dy). Thus, GR-200 detects ionizing radiation but cannot distinguish between ionizing and non-ionizing UVC radiation, while TLD-100 has limited effectiveness as a UVC radiation detector. In contrast, TLD-400 is suitable for detecting UVC radiation and TLD-200 emerges as the most favorable UVC detector, showing consistent response levels and minimal PTTL effect placed under the LDPE samples without the need of a thermal annealing treatment that makes the TLD-200 to be reusable in a low-cost measurement protocol.

Characterization of a thermally stable red-light-emitting phosphor: synthesis, photoluminescence, and thermoluminescence studies of CsCaF3 compound doped with Eu3+ for solid-state lighting applications

In this investigation, we focused on the synthesis and characterization of CsCaF3 compound doped with europium (Eu3+) ions using a solid-state route. To analyze the crystal structure of the synthesized phosphors, X-ray diffraction analysis was employed. Additionally, the doped sample underwent examination of surface morphology and elemental composition through Field Emission Scanning Electron Microscopy and EDAX mapping. The color of the pure and doped CsCaF3 sample was quantified and fitted using Color coordinate graph by the Commission Internationale de l'Eclairage (CIE). The red emission on the doped CsCaF3 compound was detected at 465 nm, which is the transition from 5D0 to 7Fj (j = 0, 1, 2, and 3). The 0.5 mol. % Eu3+ doped CsCaF3 sample was found to have a color purity of 81% and an associated color temperature of 1660 K, indicating its suitability for aesthetic lighting applications. Furthermore, thermoluminescence study, electron paramagnetic resonance (EPR), and effective atomic number (Z eff) calculations were conducted to provide valuable information for potential radiation dosimetry applications.

Raman deconvolution, radiation shielding, TL effective and dielectric investigations of Dy3+ doped alumina lead borate glasses

The objective of the current investigation was to create radiation-shielding materials that possess both thermally luminous, and dielectric behaviour. Subsequently, a glass series of Al(20-x)Pb10B70:Dyx materials was fabricated (where, x ≤ 2.5 and 0 ≤ x ≤ 1.5 in increments of 0.1, 0.5, 1, 1.5, 2, and 2.5 mol %). These materials were characterized structurally (utilizing Raman, FT-IR, DTA, SEM, XRD, and EDX), thermoluminescence, and dielectric properties. The SEM and XRD analyses demonstrate vitreous behavior. The EDX analysis provides atomic weight percent values for the chemical components. The glasses' physical properties were assessed, including their molar volume (approximately 37.48 cm3 mol−1) and density (approximately 2.725 gm/cm3). The DTA analyses of glasses indicate that the changes in GTT (approximately 286 °C) and thermal stability (∼0.656) are solely attribute to Dy3+ ions. An assortment of structural vibrations of the test glass are verified through the utilization of FT-IR and Raman analyses. The evaluation of the test glasses' micro-hardness (<5.26 GPa) was conducted utilizing ultrasonic velocities. The RPE (approximately 33.17 %) and MAC (16.9 g/cm3) indicate that the shielding behavior is also function of Dy3+ ions. The TL properties are investigated within the dose range of 5, 10, and 25 kGy of gamma irradiation. The frequency factor (3.025 × 1021 S−1) and A.E. (∼1.766 eV) of the glasses evaluated. The TL behavior of glasses is also noticed as a function of Dy3+ ions. The dielectric properties of the glasses are also analysed. The dielectric parameters such as dielectric constant (7.98), dielectric loss (0.021), ac conductivity (0.671 × 10−8 Ω−1cm−1), and A.E. (1.139 eV) evaluated. The results which include structure, elastic, radiation shielding, thermoluminescence and dialectic studies of Al(20-x)Pb10B70:Dyx glasses suggesting the glasses developed are mechanical hard, TL effective, and serve as radiation shielding dielectric resource.

Unveiling highly sensitive Dy3+ doped BaMgAl10O17 phosphor’s thermoluminescence trap features and temperature dependent luminescence for solid state lighting applications

This article explores the structural, morphological, thermoluminescence, and temperature-dependent emission properties of novel Dy3+ doped BaMgAl10O17(BAM-Dy) phosphors. Structural studies reveal that the phosphor has a similar structure to β-alumina. Rod-shaped interlinked surface morphology is a notable characteristic of the BAM-Dy samples. Incorporation of Dy3+ ions lead to the formation of distinct emission peaks (485 nm, 577 nm, and 635 nm) in the PL emission spectra. The effect of dopant concentration on the light output is crucial, and the highest PL intensity is observed for 1.5 mol% of Dy3+ concentration. The potential use of BAM-Dy phosphors for Gamma radiation detection and measurement is tested through thermoluminescence studies, which reveal high sensitivity, low threshold dose values, and exceptional response to low gamma doses, making them suitable for dosimetry applications. The investigation of trap parameters provides useful information about the number of traps, trapping mechanism, and trap energies, which is essential for in-depth study of synthesized phosphors for γ dosimetry application. The study of the effect of temperature on the luminescence behaviour is crucial for the application of phosphors in the light-emitting field. The BAM-Dy samples exhibit excellent thermal stability even at 210 °C, making them suitable for use in the field of White LEDs.

Synthesis and thermoluminescence study of Dy3+ doped ZnAl2O4 phosphor for high-dose dosimetry application

Synthesis and thermoluminescence study of Dy3+ doped ZnAl2O4 phosphor for high-dose dosimetry application

Thermoluminescence studies of Dy-doped BaAlF5 nanophosphor for radiotherapy application

Thermoluminescence studies of Dy-doped BaAlF5 nanophosphor for radiotherapy application

Structural, optical and thermoluminescence properties of amazonite

This study presents an analysis of the structural and thermoluminescence properties of amazonite, a feldspar species. The characterization was done using X-ray diffraction (XRD), X-ray fluorescence (XRF), optical spectroscopy, and vibrational spectroscopies such as Raman and Fourier Transform Infrared (FTIR). The sample exhibits a partial (Al, Si) ordenation, and contains an albite phase in addition to microcline. FTIR and Raman indicated the presence of water and OH– vibration modes. Optical absorption measurements highlighted the influence of the hydroxyl groups as catalyst for Pb transitions, contributing to the coloration of amazonite. Thermoluminescence (TL) studies were performed within a dose range from 0.1 to 10 Gy using a built-in beta source (90Sr/90Y; delivering 10 mGy/s), showing seven TL glow peaks based on non-first kinetic order. The sample exhibited a linear dose–response, with TL signals proving to be both repeatable and reproducible (CV ∼ 2%). Fading analysis showed the first two TL peaks disappear after 16 days of dark storage. Thermal quenching behavior was investigated under various heating rates, demonstrating a decrease in luminescence efficiency with increasing heating rates. Additionally, the activation energies were determined using different methods, and the amazonite TL glow curve presented activation energies values within 0.7 to 2 eV.

Thermoluminescence studies of a Gothic church in Świebodzin from Silesia in Poland

The paper presents thermoluminescence (TL) studies that aim to establish the possibility of using such analysis to determine the date of the construction, transformation and/or rebuilding of a historical church. The determination of the age of building structures using the form of absolute dating that is now used by architects and archeologists is difficult and complex. A relatively large error of estimation can be observed in archeological studies. In the case of samples from the Middle Ages, such errors are not acceptable. The authors attempted to develop an alternative spectroscopic TL method for such studies, and proposed that the composition of bricks should be measured using X-ray diffraction, electron microscopy (EM) and TL spectra. The bricks for the testing were taken from internal walls and the walls in the attics of churches, i.e. from places built during the last stage of construction works. The TL measurements were made using x-ray and β source excitation within the temperature range of 25–500°C. Two different sizes of grains were studied: small (∼0.1 mm) and large (∼0.5 mm). A gothic church in Świebodzin from 1555, which has a well-known history of its construction, was selected for the investigations. Due to the fact that this church is 326 years younger than the two churches evaluated and described in [1], the composition of its bricks could be different. Therefore, the authors decided to compare the XRD data, EM results and TL spectra for bricks taken from all three churches. The intensities of the TL and the integrated TL intensities were determined. The measurement results are important for creating a relationship between the TL intensity and the date a building object was constructed. Moreover, thanks to this it was possible to verify the construction date of Saski Palace in Warsaw.

Exploring beta irradiation responses in Sr2+-Doped hydroxyapatite: A thermoluminescence study

This research investigates the structural and thermoluminescence (TL) properties of Sr2+-doped Ca5(PO4)3OH (HAp) phosphors. X-ray diffraction (XRD) analysis confirms that HAp has a hexagonal structure with a P63/m space group. The TL behaviour of HAp:Sr2+ phosphors is examined under beta irradiation in the temperature range of 25–500 °C. The study reveals three TL glow peaks at temperatures of 75, 212, and 296 °C. Investigation of TL responses across heating rates (HR) ranging from 0.1 to 5 °C/s shows that higher HRs result in increased maximum TL peak temperatures and reduced TL intensities. This trend suggests an augmented contribution from non-radiative transitions as the heating rate increases. Importantly, no evidence of thermal quenching is found in the HAp samples. Two different methods, Hoogenstraaten's and Booth-Bohun-Porfianovitch, yield consistent activation energy values of 0.50, 1.22, 1.67 eV, and 0.48, 1.19, 1.63 eV, respectively. Reusability assessments indicate a standard deviation of less than 5 %, confirming the reliability of the materials. Tm−Tstop analysis reveals a continuous distribution of trap levels. TL properties in HAp samples have been comprehensively characterized, contributing not only to enhancing our understanding of their behaviour, but also highlighting their potential applications in various areas. The findings of this study have provided valuable insight into the development of efficient catalysts that are suitable for a variety of applications.

A first look at phototransferred thermoluminescence of rose quartz

We report a preliminary study of phototransferred thermoluminescence (PTTL) induced by 470 nm light source in rose quartz. The glow curve corresponding to 1 Gy consists of five peaks at 76, 115, 180, 290 and 423 °C labelled I through V in that order. In the PTTL experiments employing blue light. PTTL was regenerated at peak I following preheating to remove peak I only and at peaks I and II otherwise. The dependence of the PTTL intensity on duration of illumination is analyzed in terms of a system of one acceptor and two donors in both cases. The mechanisms for the PTTL phenomena in the rose quartz are comprehensively discussed in this paper.

Charge carrier trapping management in Bi3+ and lanthanides doped Li(Sc,Lu)GeO4 for x-ray imaging, anti-counterfeiting, and force recording

Discovering energy storage materials with rationally controlled trapping and de-trapping of electrons and holes upon x-rays, UV-light, or mechanical force stimulation is challenging. Such materials enable promising applications in various fields, for instance in multimode anti-counterfeiting, x-ray imaging, and non-real-time force recording. In this work, photoluminescence spectroscopy, the refined chemical shift model, and thermoluminescence studies will be combined to establish the vacuum referred binding energy (VRBE) diagrams for the LiSc1−xLuxGeO4 family of compounds containing the energy level locations of Bi2+, Bi3+, and the lanthanides. The established VRBE diagrams are used to rationally develop Bi3+ and lanthanides doped LiSc1−xLuxGeO4 storage phosphors and to understand trapping and de-trapping processes of charge carriers with various physical excitation means. The thermoluminescence intensity of x-ray irradiated LiSc0.25Lu0.75GeO4:0.001Bi3+,0.001Eu3+ is about two times higher than that of the state-of-the-art x-ray storage phosphor BaFBr(I):Eu2+. Particularly, a force induced charge carrier storage phenomenon appears in Eu3+ co-doped LiSc1−xLuxGeO4. Proof-of-concept non-real-time force recording, anti-counterfeiting, and x-ray imaging applications will be demonstrated. This work not only deepens our understanding of the capturing and de-trapping processes of electrons and holes with various physical excitation sources, but can also trigger scientists to rationally discover new storage phosphors by exploiting the VRBEs of bismuth and lanthanide levels.

Effect of temperature on lanthanide charge transition levels and vacuum referred binding energies

Location of lanthanide levels in the bandgap, vacuum referred binding energy (VRBE) in the lanthanide ground state and energy of lanthanide charge transition levels (CTLs) are just three different namings for the same concept. A concept of importance for the performance of lanthanide activated compounds. Energy differences of CTLs with the conduction band bottom and valence band top are important when it concerns e.g. lanthanide luminescence, charge carrier trapping, and valence stability. Effect of temperature on CTL energy or VRBE has so far never been addressed despite that luminescence application and thermoluminescence studies may span a temperature range from 10 K to 1000 K. In this work information on the bandgap (or energy of host exciton creation) around 10 K and at RT in compounds is gathered to demonstrate that bandgap decreases by 0.1 eV to 0.3 eV when temperature increases to RT. A similar decrease will be demonstrated for the energy of electron transfer from the VB to a trivalent lanthanide. The findings have consequences for VRBE-diagram construction, i.e. the experimental parameters for such construction should all apply to the same temperature. They also have consequences on how to relate luminescence thermal quenching energy barriers and TL derived electron and hole trap depths with a VRBE diagram. By proper evaluating the effects of temperature, accuracy of VRBE diagrams and consistency with luminescence and thermoluminescence data can be improved.

Synthesis and Thermoluminescence Studies of Dy3+ Doped Bi2O3 Nanophosphors

Detailed Thermoluminescence studies of Bi2O3 doped with Dy3+ synthesized by solution combustion method and irradiated with -rays and β-rays for doses in the range from a few Gy to KGy was done in the current work. Powder X-ray diffraction (PXRD) analysis is used to calculate the average particle size and was determined to be in the range 13-30 nm. Thermoluminescence (TL) characteristics of β-rayed Bi2O3: Dy3+ doped samples for dose of 1 Gy to 20 Gy are studied. In all -irradiated Bi2O3 : Dy3+ doped samples, at ~145 oC (Tg1) and ~155 oC (Tg2) two significant and well resolved TL glow peaks were observed. Also, the TL intensity is found to increase with dopant concentration up to 5 mol % and then decreases due to quenching. The peak position of both the glow peaks (Tg1 and Tg2) is almost stable for the complete dose range. The activation energy and frequency factors are found to be 0.79 eV and 1.75×1015 s-1 respectively. These values are in very good agreement with those values calculated by peak shape methods and are found to be 0.73 eV and 1.70×1015 s-1 respectively.