Multimode Luminesce Tailoring PMA4Na(In,Sb)Cl8 Organic-inorganic Hybrid Metal Halide via Rigid Benzene Ring Induced Local Lattice Distortion.

Low dimensional organic-inorganic hybrid metal halide materials have attracted extensive attention due to their superior optoelectronic properties. However, low photoluminescence quantum yields (PLQYs) caused by parity-forbidden transition hinder their further application in optoelectronic devices. Herein, a novel yellow-emitting PMA4Na(In,Sb)Cl8 (C7H10N+, PMA+) low-dimensional OIMHs single crystal with a PLQY as high as 88% was successfully designed and synthesized, originating from the fact that the doping of Sb3+ effectively relaxes the parity-forbidden transition by strong spin-orbit (SO) coupling and Jahn-Teller (JT) interaction. The as-prepared crystal shows an efficient dual emission peaking 495 and 560 nm at low temperature, which are ascribed to different levels of 3P1 → 1S0 transitions of Sb3+ in [SbCl6]3- octahedral caused by JT deformation. Moreover, wide-range luminescence tailoring from cyan to orange can be achieved through adjusting excitation energy and temperature because of flexible [SbCl6]3- octahedral in the PNIC lattice. Based on a relative stiff lattice environment, the 560 nm yellow emission under 350 nm light excitation exhibits abnormal anti-thermal quenching from 8 to 400 K owing to the suppression of non-radiative transition. The multimode luminescence regulation enriches PMA4Na(In,Sb)Cl8 great potential in the field of optoelectronics such as temperature sensing,  low temperature anti-counterfeiting and WLED applications.

Effect of annealing temperature on the optoelectrical synapse behaviors of A-ZnO microtube.

Optoelectronic synapses with fast response, low power consumption, and memory function hold great potential in the future of artificial intelligence technologies. Herein, a strategy of annealing in oxygen ambient at different temperatures is presented to improve the optoelectronic synaptic behaviors of acceptor-rich ZnO (A-ZnO) microtubes. The basic synaptic functions of as-grown and annealed A-ZnO microtubes including excitatory postsynaptic current (EPSC), short-term memory (STM) to long-term memory (LTM) conversion, and paired-pulse facilitation (PPF), were successfully emulated. The results show that the annealing temperature of 600 °C yields high figures of merit compared to other annealed A-ZnO microtubes. The 4-fold and 20-fold enhancement dependent on the light pulse duration time and energy density have been achieved in the 600 °C annealed A-ZnO microtube, respectively. Furthermore, the device exhibited a PPF index of up to 238% and achieved four cycles of "learning-forgetting" process, proving its capability for optical information storage. The free exciton (FX) and donor-acceptor pair (DAP) concentrations significantly influenced the persistent photoconductivity (PPC) behavior of A-ZnO microtubes. Therefore, the LTM response can be controlled by the adjustment of numbers, powers, and interval time of the optical stimulation. This work outlines a strategy to improve the EPSC response through defect control, representing a step towards applications in the field of optoelectronic synaptic device.

Adjusting luminescence properties of ZnAl2O4:Mn2+(Mn4+), Li+ phosphors through cation substitution.

ZnAl2O4 with a typical spinel structure is highly expected to be a novel rare-earth-free ion-activated oxide phosphor with red emission, which holds high actual meaning for advancing phosphor-converted light-emitting diode (pc-LED) lighting. Among the rare-earth-free activators, Mn4+ ions have emerged as one of the most promising activators. Considering the price advantage of MnCO3 generating Mn2+ ions and the charge compensation effect potentially obtaining Mn4+ ions from Mn2+ ions, this research delves into a collection of ZnAl2O4:Mn2+(Mn4+), x Li+ (x = 0%-40%) phosphors with Li+ as co-dopant and MnCO3 as Mn2+ dopant source prepared by a high temperature solid-state reaction method. The lattice structure was investigated using X-ray diffraction (XRD), photoluminescence (PL), and photoluminescence excitation (PLE) spectroscopy. Results suggest a relatively high probability of Li+ ions occupying Zn2+ lattice sites. Furthermore, Li+ ion doping was assuredly found to facilitate the oxidization of Mn2+ to Mn4+, leading to a shift of luminescence peak from 516 to 656 nm. An intriguing phenomenon that the emission color changed with the Li+ doping content was also observed. Meanwhile, the luminescence intensity and quantum yield (QY) at different temperatures, as well as the relevant thermal quenching mechanism, were determined and elucidated detailedly.

Negative Thermal Quenching of Photoluminescence: An Evaluation from the Macroscopic Viewpoint.

Negative thermal quenching (NTQ) denotes that the integral emission spectral intensity of a given phosphor increases continuously with increasing temperature up to a certain elevated temperature. NTQ has been the subject of intensive investigations in recent years, and a large number of phosphors are reported to have exhibited NTQ. In this paper, a collection of results in the archival literature about NTQ of specific phosphors is discussed from a macroscopic viewpoint, focusing on the following three aspects: (1) Could the NTQ of a given phosphor be reproducible? (2) Could the associated data for a given phosphor exhibiting NTQ be in line with the law of the conservation of energy? (3) Could the NTQ of a given phosphor be demonstrated in a prototype WLED device? By analyzing typical cases based on common sense, we hope to increase awareness of the issues with papers reporting the NTQ of specific phosphors based on spectral intensity, along with the importance of maintaining stable and consistent measurement conditions in temperature-dependent spectral intensity measurement, which is a prerequisite for the validity of the measurement results.

Phosphate phosphors with anti-thermal quenching properties for urban ecological lighting.

White light-emitting diode (LED) for night lighting disrupts photoperiod in plants, which affects the plant's photosynthesis. Therefore, it is necessary to find a new type of white LED with little effect on plant photosynthesis. In this study, a series of phosphate phosphors Ca9NaY2/3(PO4)7:Dy3+ (CNYP:Dy3+) were synthesized. Cation Li+ substitute Na+ were used to improve the luminescence properties of CNYP:Dy3+ phosphor. The CNYP:Dy3+ phosphor exhibits visible white light emission with emission peaks at 480 nm (blue light) and 570 nm (yellow light) excited by the near ultraviolet light 350 nm. The optimal concentration of Dy3+ was 0.10 mol, and the mechanism of concentration quenching was evaluated as energy migration among the nearest or next-nearest Dy3+. The substitution of Na+ by Li+ of CNYP:0.10Dy3+ improves the internal quantum efficiency from 30.24 % to 59.05 %, and presents good near-zero thermal quenching performance at 423 K. To assess the suitability of this phosphor for urban ecological lighting, the spectrum resemblance (SR) index between the electroluminescence spectrum of the prepared pc-LED and the absorption spectra of chlorophyll a and b was evaluated as 6.63 % and 18.61 %, respectively. This work exhibits a feasible scheme for the development of urban ecological lighting.

Overcoming Thermal Quenching in X-ray Scintillators through Multi-Excited State Switching.

X-ray scintillators have gained significant attention in medical diagnostics and industrial applications. Despite their widespread utility, scintillator development faces a significant hurdle when exposed to elevated temperatures, as it usually results in reduced scintillation efficiency and diminished luminescence output. Here we report a molecular design strategy based on a hybrid perovskite (TpyBiCl5) that overcomes thermal quenching through multi-excited state switching. The structure of perovskite provides a platform to modulate the luminescence centers. The rigid framework constructed by this perovskite structure stabilized its triplet states, resulting in TpyBiCl5 exhibiting an approximately 12 times higher (45 % vs. 3.8 %) photoluminescence quantum yield of room temperature phosphorescence than that of its organic ligand (Tpy). Most importantly, the interactions between the components of this perovskite enable the mixing of different excited states, which has been revealed by experimental and theoretical investigations. The TpyBiCl5 scintillator exhibits a detection limit of 38.92 nGy s-1 at 213 K and a detection limit of 196.31 nGy s-1 at 353 K through scintillation mode switching between thermally activated delayed fluorescence and phosphorescence. This work opens up the possibility of solving the thermal quenching in X-ray scintillators by tuning different excited states.

Zero Thermal Quenching Phenomenon of Green Emitting Carbon Dots with High Biocompatibility and Stable Multicolor Biological Imaging in a Hot Environment.

Carbon dots are emerging fluorescent nanomaterials with unique physical and chemical properties and a wide range of applications. Herein, we have designed and successfully synthesized thermally stable green emissive nitrogen-doped carbon dots (NCDs) with a photoluminescent quantum yield of 11.32% through facile solvent-free carbonization. NCDs demonstrated zero thermal quenching upon various temperatures modulating from 20 to 80 °C. The green emissive NCDs perform very stably even after heating them at 80 °C for 1 h. The thermal stability mechanism demonstrates that C═O and C═N functional groups control the particle aggregation and protect the fluorescent hub from photo-oxidation and thermal oxidation. Highly biocompatible CDs exhibit bright, stable, and multicolor emissions in T-ca cells under hot circumstances (25-45 °C). Additionally, NCDs offer long-term stability in the biosystem, as evidenced by the fact that the cell retains its brightness about 70% after prolonging the incubation time to 8 days. Furthermore, the fluorescent NCDs are utilized as in vivo imaging agents in the hot environment as they display bright and thermally stable imaging (27-45 °C) under 488 nm excitation. The results confirmed that the produced thermally stable NCDs could be used in biology and related medical fields that require hot environment imaging.

Multimode Luminescence Tailoring and Improvement of Cs2 NaHoCl6 Cryolite Crystals via Sb3+ /Yb3+ Alloying for Versatile Photoelectric Applications.

Lead-free halide double perovskites are currently gaining significant attention owing to their exceptional environmental friendliness, structural adjustability as well as self-trapped exciton emission. However, stable and efficient double perovskite with multimode luminescence and tunable spectra are still urgently needed for multifunctional photoelectric application. Herein, holmium based cryolite materials (Cs2 NaHoCl6 ) with anti-thermal quenching and multimode photoluminescence were successfully synthesized. By the further alloying of Sb3+ (s-p transitions) and Yb3+ (f-f transitions) ions, its luminescence properties can be well modulated, originating from tailoring band gap structure and enriching electron transition channels. Upon Sb3+ substitution in Cs2 NaHoCl6 , additional absorption peaking at 334 nm results in the tremendous increase of photoluminescence quantum yield (PLQY). Meanwhile, not only the typical NIR emission around 980 nm of Ho3+ is enhanced, but also the red and NIR emissions show a diverse range of anti-thermal quenching photoluminescence behaviors. Furthermore, through designing Yb3+ doping, the up-conversion photoluminescence can be triggered by changing excitation laser power density (yellow-to-orange) and Yb3+ doping concentration (red-to-green). Through a combined experimental-theoretical approach, the related luminescence mechanism is revealed. In general, by alloying Sb3+ /Yb3+ in Cs2 NaHoCl6 , abundant energy level ladders are constructed and more luminescence modes are derived, demonstrating great potential in multifunctional photoelectric applications.

Temperature-Dependent Phonon Scattering and Photoluminescence in Vertical MoS2/WSe2 Heterostructures.

Transition metal dichalcogenide (TMD) monolayers and their heterostructures have attracted considerable attention due to their distinct properties. In this work, we performed a systematic investigation of MoS2/WSe2 heterostructures, focusing on their temperature-dependent Raman and photoluminescence (PL) characteristics in the range of 79 to 473 K. Our Raman analysis revealed that both the longitudinal and transverse modes of the heterostructure exhibit linear shifts towards low frequencies with increasing temperatures. The peak position and intensity of PL spectra also showed pronounced temperature dependency. The activation energy of thermal-quenching-induced PL emissions was estimated as 61.5 meV and 82.6 meV for WSe2 and MoS2, respectively. Additionally, we observed that the spectral full width at half maximum (FWHM) of Raman and PL peaks increases as the temperature increases, and these broadenings can be attributed to the phonon interaction and the expansion of the heterostructure's thermal coefficients. This work provides valuable insights into the interlayer coupling of van der Waals heterostructures, which is essential for understanding their potential applications in extreme temperatures.

Negative Thermal Quenching in Quantum-Cutting Yb3+-Doped CsPb(Cl1-xBrx)3 Perovskite Nanocrystals.

Ytterbium-doped all-inorganic lead-halide perovskites (Yb3+:CsPb(Cl1-xBrx)3) show broadband absorption and exceptionally high near-infrared photoluminescence quantum yields, providing opportunities for solar spectral shaping to improve photovoltaic power conversion efficiencies. Here, we report that Yb3+:CsPb(Cl1-xBrx)3 NCs also show extremely strong negative thermal quenching of the Yb3+ luminescence, with intensities at room temperature >100 times those at 5 K for some compositions. Analysis of this temperature dependence as a function of x shows that it stems from thermally activated quantum cutting related to the temperature dependence of the spectral overlap between the PL of the perovskite (donor) and the simultaneous-pair absorption of two Yb3+ ions (acceptor). In the Yb3+:CsPbBr3 limit, this spectral overlap goes to zero at 5 K, such that only single-Yb3+ sensitization requiring massive phonon emission occurs. At room temperature, Yb3+ PL in this composition is enhanced ∼135-fold by thermally activated quantum cutting, highlighting the extreme efficiency of quantum cutting relative to single-Yb3+ sensitization. These results advance the fundamental mechanistic understanding of quantum cutting in doped perovskites, with potential ramifications for solar and photonics technologies.

Effects of framework dopants on luminescent properties of red nitride phosphors via band structure modelling.

Currently, researchers have been able to manipulate the luminescent properties and thermal stability of nitride red phosphor Sr2Si5N8:Eu2+ through rare earth doping. However, there is limited research on the doping of its framework. This work investigated the crystal structure, band structure, and luminescence properties of Sr2Si5N8: Eu2+ and its framework doped systems. We selected B, C, and O as doping elements because the corresponding formation energies of these elements doped structures are relatively low. Then, we calculated the band structures of various doped systems in both the ground and excited states. This analysis aimed to investigate their luminescent properties using the configuration coordinate diagram. The results show that doping with B, C, or O has minimal effect on the emission peak width. The thermal quenching resistance of the B- or C-doped system was enhanced due to the increased energy differences between the 5d energy level of the electron-filled state in the excited state and the bottom of the conduction band, compared to the undoped system. However, the thermal quenching resistance of the O-doped system varies depending on the position of the silicon vacancy. The work indicates that framework doping can also improve the thermal quenching resistance of phosphors besides rare earth ions doping.

Fluorine Passivation Inhibits "Particle Talking" Behaviors under Thermal and Electrical Conditions of Pure Blue Mixed Halide Perovskite Nanocrystals.

Owing to outstanding optoelectronic properties, lead halide perovskite nanocrystals (PNCs) are considered promising emitters for next-generation displays. However, the development of pure blue (460-470 nm) perovskite nanocrystal light-emitting diodes (PNC-LEDs), which correspond to the requirements of Rec. 2020 standard, lag far behind that of their green and red counterparts. Here, pure blue CsPb(Br/Cl)3 nanocrystals with remarkable optical performance are demonstrated by a facile fluorine passivation strategy. Prominently, the fluorine passivation on halide vacancies and strong bonding of Pb-F intensely enhance crystal structure stability and inhibit "particle talking" behaviors under both thermal and electrical conditions. Fluorine-based PNCs with high resistance of luminescence thermal quenching retain 70% of photoluminescent intensity when heated to 343 K, which can be attributed to the elevated activation energy for carrier trapping and unchanged grain size. Fluorine-based PNC-LEDs also exhibit stable pure blue electroluminescence (EL) emission with sevenfold promoted luminance and external quantum efficiencies (EQEs), where the suppression of ion migration is further evidenced by a lateral structure device with applied polarizing potential.

Novel Red-Emitting Eu3+-Doped Y2(WxMo1-xO4)3 Phosphor with High Conversion Efficiency for Lighting and Display Applications.

In this study, a series of trivalent europium-doped tungstate and molybdate samples were synthesized using an improved sol-gel and high-temperature solid-state reaction method. The samples had different W/Mo ratios and were calcined at various temperatures ranging from 800 to 1000 °C. The effects of these variables on the crystal structure and photoluminescence characteristics of the samples were investigated. It was found that a doping concentration of 50% for europium yielded the best quantum efficiency based on previous research. The crystal structures were found to be dependent on the W/Mo ratio and calcination temperature. Samples with x ≤ 0.5 had a monoclinic lattice structure that did not change with calcination temperature. Samples with x > 0.75 had a tetragonal structure that remained unchanged with calcination temperature. However, samples with x = 0.75 had their crystal structure solely dependent on the calcination temperature. At 800-900 °C, the crystal structure was tetragonal, while at 1000 °C, it was monoclinic. Photoluminescence behavior was found to correlate with crystal structure and grain size. The tetragonal structure had significantly higher internal quantum efficiency than the monoclinic structure, and smaller grain size had higher internal quantum efficiency than larger grain size. External quantum efficiency initially increased with increasing grain size and then decreased. The highest external quantum efficiency was observed at a calcination temperature of 900 °C. These findings provide insight into the factors affecting the crystal structure and photoluminescence behavior in trivalent europium-doped tungstate and molybdate systems.

Nano-Coprecipitation Route Synthesis of Highly-Efficient Submicron (Sr,Ba)2SiO4:Eu2+ Phosphors with Enhanced Thermal Stability for MicroLED Color Conversion.

As the size of MicroLED chips shrinks below 50 µm, the emergence of quantum dots (QDs)-based color conversion with narrow-band emission and nanoscale size properties has become one of the powerful full-color solutions for MicroLED displays. However, the stability and toxicity of quantum dots limit their application in full-color MicroLEDs. The phosphor-based conversion has the prominent features of high thermal and chemical stability relative to those of QD-based conversion. Nevertheless, the particle size of phosphor prepared by a traditional high-temperature solid-state reaction (SSR) is equivalent to or even larger than that of the MicroLED chip. In this work, we propose a strategy to prepare (Sr,Ba)2SiO4:0.03Eu2+ (SBSO:0.03Eu2+) submicron phosphors via a nano-coprecipitation method (NCP) using nanoSi3N4 as the Si source materials, which enables the particle size to be reduced while maintaining the luminescence efficiency. The optimized SBSO:0.03Eu2+ has an average size of less than 2 µm, showing a narrow band green emission centered at 522 nm, with a full width at half-maximum of 60 nm and an external quantum efficiency of 40.2%. At 150 °C, its thermal stability is greatly enhanced to 80.2% of the emission at room temperature. Further, the mechanism for defect compensation thermal stability is investigated. By employing it as a green emitter, we fabricate a high-performance white LED device (WLED) with a wide color gamut of 86.7% NTSC. This work for the preparation of high-brightness and thermal stability enhancement SBSO:0.03Eu2+ phosphor not only provides a facile method but also helps to provide an alternative green fluorescent material for the realization of full color MicroLED.

Frenkel Defect-modulated Anti-thermal Quenching Luminescence in Lanthanide-doped Sc2 (WO4 )3.

Although large amount of effort has been invested in combating thermal quenching that severely degrades the performance of luminescent materials particularly at high temperatures, not much affirmative progress has been realized. Herein, we demonstrate that the Frenkel defect formed via controlled annealing of Sc2 (WO4 )3 :Ln (Ln=Yb, Er, Eu, Tb, Sm), can work as energy reservoir and back-transfer the stored excitation energy to Ln3+ upon heating. Therefore, except routine anti-thermal quenching, thermally enhanced 415-fold downshifting and 405-fold upconversion luminescence are even obtained in Sc2 (WO4 )3 :Yb/Er, which has set a record of both the Yb3+ -Er3+ energy transfer efficiency (>85 %) and the working temperature at 500 and 1073 K, respectively. Moreover, this design strategy is extendable to other hosts possessing Frenkel defect, and modulation of which directly determines whether enhanced or decreased luminescence can be obtained. This discovery has paved new avenues to reliable generation of high-temperature luminescence.

Realization of 1.54-µm Light-Emitting Diodes Based on Er3+ /Yb3+ Co-Doped CsPbCl3 Films.

Erbium ions (Er3+ , 1.54 µm) electric pumped light sources with excellent optical properties and a simple fabrication process are urgently desired to satisfy the development of silicon-based integration photonics. The previous Er-based electroluminescence devices are mainly based on Er-complexes or Er-doped oxide compounds, which usually suffer from low external quantum efficiency(EQE)or high applied voltage etc. In this work, a novel type of Er3+ /Yb3+ co-doped lead-halide perovskite films (Er3+ /Yb3+ :CsPbCl3 ) with the maximum photoluminescence quantum yield of 30.12% are prepared by a simple two-step solution-coating method and the corresponding light emitting diodes (Er-PeLEDs) are fabricated, which demonstrate an almost pure 1.54-µm emission and a peak EQE up to 0.366% at a low applied voltage of 1.4 V. Strong negative thermal quenching effect may help Er-PeLEDs suppress Joule heating quenching. These excellent LED properties benefit mainly from the outstanding regulatory performance of acetate to perovskite films, the excellent semiconductor behavior and strong ionic property of the perovskite, and the involvement of Yb3+ ions, which can directly and efficiently transfer the exciton energy to Er3+ through a quantum cutting process. Overall, the realization of 1.54-µm Er-PeLEDs offers new opportunities for silicon-based integrated light sources.

Improved Photoluminescence Performance of Eu3+-Doped Y2(MoO4)3 Red-Emitting Phosphor via Orderly Arrangement of the Crystal Lattice.

In this study, we developed a technology for broadening the 465 nm and 535 nm excitation peaks of Eu3+:Y2(MoO4)3 via crystal lattice orderly arrangement. This was achieved by powder particle aggregation and diffusion at a high temperature to form a ceramic structure. The powdered Eu3+:Y2(MoO4)3 was synthesized using the combination of a sol-gel process and the high-temperature solid-state reaction method, and it then became ceramic via a sintering process. Compared with the Eu3+:Y2(MoO4)3 powder, the full width at half maximum (FWHM) of the excitation peak of the ceramic was broadened by two- to three-fold. In addition, the absorption efficiency of the ceramic was increased from 15% to 70%, while the internal quantum efficiency reduced slightly from 95% to 90%, and the external quantum efficiency was enhanced from 20% to 61%. More interestingly, the Eu3+:Y2(MoO4)3 ceramic material showed little thermal quenching below a temperature of 473 K, making it useful for high-lumen output operating at a high temperature.

Highly Effective Hybrid Copper(I) Iodide Cluster Emitter with Negative Thermal Quenched Phosphorescence for X-Ray Imaging.

The low efficiency triplet emission of hybrid copper(I) iodide clusters is a critical obstacle to their further practical optoelectronic application. Herein, we present an efficient hybrid copper(I) iodide cluster emitter (DBA)4 Cu4 I4 , where the cooperation of excited state structure reorganization and the metallophilicity interaction enables ultra-bright triplet yellow-orange emission with a photoluminescence quantum yield over 94.9 %, and the phonon-assisted de-trapping process of exciton induces the negative thermal quenching effect at 80-300 K. We also investigate the potential of this emitter for X-ray imaging. The (DBA)4 Cu4 I4 wafer demonstrates a light yield higher than 104  photons MeV-1 and a high spatial resolution of ≈5.0 lp mm-1 , showing great potential in practical X-ray imaging applications. Our new copper(I) iodide cluster emitter can serve as a model for investigating the thermodynamic mechanism of photoluminescence in hybrid copper(I) halide phosphorescence materials.

Highly Luminescent Earth-Benign Organometallic Manganese Halide Crystals with Ultrahigh Thermal Stability of Emission from 4 to 623 K.

The phosphor-converted light-emitting diode (PC-LED) has become an indispensable solid-state lighting and display technologies in the modern society. Nevertheless, the use of scarce rare-earth elements and the thermal quenching (TQ) behavior are still two most crucial issues yet to be solved. Here, this work successfully demonstrates a highly efficient and thermally stable green emissive MnI2 (XanPO) crystals showing a notable photoluminescence quantum yield (PLQY) of 94% and a super TQ resistance from 4 to 623 K. This unprecedented superior thermal stability is attributed to the low electron-phonon coupling and the unique rigid crystal structure of MnI2 (XanPO) over the whole temperature range based on the temperature-dependent photoluminescence (PL) and single crystal X-ray diffraction (SCXRD) analyses. Considering these appealing properties, green PC-LEDs with a power efficacy of 102.5 lm W-1 , an external quantum efficiency (EQE) of 22.7% and a peak luminance up to 7750 000 cd m-2 are fabricated by integrating MnI2 (XanPO) with commercial blue LEDs. Moreover, the applicability of MnI2 (XanPO) in both micro-LEDs and organic light-emitting diodes (OLEDs) is also demonstrated. In a nutshell, this study uncovers a candidate of highly luminescent and TQ resistant manganese halide suitable for a variety of emission applications.

Effect of Re-sintering on the morphological and thermoluminescence properties of the ALOX-520 detector.

Significant research is being conducted on new materials suitable for dosimetry in recent decades with particular focus on their luminescent properties. For instance, a new ceramic detector, aluminum oxide 520 (ALOX-520), was developed at CDTN in 2011 using the sol-gel method. The detectors were doped with C, Fe, Mg, Ca, Cr, Ni, and Mo impurities that generated the necessary dosimetric trap levels to enhance the luminescence effects. Consequently, the resultant material was appropriate for the quantification of ionizing radiation fields by both thermally and optically stimulated luminescence techniques. Originally, ALOX 520 was sintered at 2023 K under a highly reducing atmosphere. At the end of this process, it exhibited important dosimetric properties, as already described in existing literature. The objective of this study is to conduct tests at higher temperatures in vacuum to investigate the effect of thermal treatments under these conditions on the structural and dosimetric properties of the material. Accordingly, ALOX-520 was re-sintered at high temperatures and the changes in its physical, morphological, and dosimetric properties were analyzed. ALOX 520T exhibited better dosimetric properties in terms of homogeneity, reproducibility, linearity, and signal fading. Physically, an increase in the detection threshold value of ALOX-520T could be linked to a decrease in the sensitivity of this detector. The energy dependence, the thermal quenching correction, and kinetic studies for ALOX-520T conducted as part of this work are original. However, the obtained results are consistent with those reported in the literature for α-Al2O3 ceramic detectors. XRD and XRF analyses demonstrated that the thermal treatment did not change the crystalline structure or composition of the material. All the results indicate that an appropriate thermal treatment could improve the dosimetric properties of the ALOX-520 detector without causing significant changes in its crystalline structure.