Light Output Research Articles

Luminescence and scintillation properties of TlCdCl3:Sb crystals

An ideal scintillator for X- and gamma-ray detection should have a high light yield and a high effective atomic number (Zeff). In this study, we developed undoped TlCdCl3 crystals and TlCdCl3:Sb (Sb: 0.5, 1.0 and 1.5 mol%) crystals with high Zeff (TlCdCl3:68.7), as candidate scintillators. The crystals were grown using the self-seeding solidification method, and their photoluminescence (PL) and scintillation properties were investigated. For the undoped TlCdCl3 crystals, emission peaks were observed at 460 nm and 485 nm in the PL and X-ray-induced radioluminescence (XRL) spectra, respectively. For the TlCdCl3:Sb crystals, the PL spectra showed emission peaks at 480, 480 and 500 nm, while the XRL spectra exhibited peaks at approximately 510 nm. The emission bands of the TlCdCl3:Sb crystals were shifted to longer wavelengths than those of the undoped TlCdCl3 crystals. The scintillation decay time constants for the undoped TlCdCl3 crystals were 51 and 2613 ns, whereas for the TlCdCl3:Sb crystals, they were in the range of 65–81 and 4550–7350 ns. These results suggest that the incorporation of Sb3+ ions induces long components of several thousand nanoseconds. The redshift and appearance of these long components indicate that Sb3+ ions act as new luminescence centers in the undoped TlCdCl3 crystal. The scintillation light yield of the TlCdCl3:Sb 1.0 mol% crystal was measured at 10,300 photons/MeV. The doping of Sb3+ ions into the TlCdCl3 lattice improved the scintillation light yield by up to four times compared to the undoped TlCdCl3 crystal.

Impurity-enhanced core valence luminescence via Zn-doping in cesium magnesium chlorides

Scintillators with faster timing capabilities are currently in high demand for use in radiation detection systems in the fields of nuclear and medical physics. The limited number of suitable materials that meet the performance criteria of next generation detection systems presents an opportunity for discovery of new fast scintillator materials. In this work, the effects of doping several ultrafast core-valence luminescent (CVL) scintillators with divalent Zn is explored. Three compounds are investigated – CsMgCl3, Cs2MgCl4, and Cs3MgCl5 – and single crystals of each doped with 5 mol% Zn are grown via the Bridgman method. Additionally, mixing across the full range of concentrations (from 0 % to 100 % Zn) is explored in the Cs2Mg1-xZnxCl4 and Cs3Mg1-xZnxCl5 systems. For low concentrations of Zn, light yields of all three compounds are enhanced (by up to ∼60 %) compared to the pure crystals, achieving what we believe to be the brightest known CVL, CsMgCl3:Zn 5 % (3400 ± 170 ph/MeV light yield). More importantly, Zn doping does not affect the ultrafast timing properties, with each composition maintaining a single-component decay time around 1–3 ns. A sub-100 ps coincidence time resolution (CTR) is also achieved with CsMgCl3:Zn 5 %. The results of this work reveal a new avenue towards obtaining brighter CVL materials, which could open up possibilities for more advanced ultrafast scintillators to be discovered moving forward.

Developing Cost-Effective Digital PET Scanners: Challenges and Solutions

When compared to older analog systems, digital Positron Emission Tomography (PET) scanners provide much improved resolution, sensitivity, and diagnostic capabilities. This represents a major leap in the field of medical imaging. On the other hand, the development of digital PET scanners that are both cost-effective and accessible presents a number of issues that need to be solved in order to make these technologies more accessible and inexpensive. The creation of digital PET scanners that are low-cost is the subject of this research, which investigates the primary obstacles and possible solutions to these problems. Wce at a cheaper cost. In this respect, it is essential to make advancements in scintillator materials, such as the creation of new kinds of crystals that have a higher light output and a lower cost. In addition, developments in semiconductor technology and the incorporation of circuits that are more efficient in terms of cost may contribute to a reduction in the total cost of digital PET scanners. The complexity of the imaging systems, in addition to the high manufacturing costs that are often connected with them, is another key hurdle. In order to process and reconstruct pictures of a high quality, digital PET scanners need the use of complicated hardware setups and advanced software algorithms. A reduction in production costs may be achieved by the use of modular and scalable designs, as well as the streamlining of the design and manufacturing processes. Modular systems make it possible to make gradual improvements and repairs, which may be more cost-effective than replacing complete components that are being replaced.

Hybrid Eu(II)-bromide scintillators with efficient 5d-4f bandgap transition for X-ray imaging

Luminescent metal halides are attracting growing attention as scintillators for X-ray imaging in safety inspection, medical diagnosis, etc. Here we present brand-new hybrid Eu(II)-bromide scintillators, 1D type [Et4N]EuBr3·MeOH and 0D type [Me4N]6Eu5Br16·MeOH, with spin-allowed 5d-4f bandgap transition emission toward simplified carrier transport during scintillation process. The 1D/0D structures with edge/face -sharing [EuBr6]4− octahedra further contribute to lowing bandgaps and enhancing quantum confinement effect, enabling efficient scintillation performance (light yield ~73100 ± 800 Ph MeV−1, detect limit ~18.6 nGy s−1, X-ray afterglow ~ 1% @ 9.6 μs). We demonstrate the X-ray imaging with 27.3 lp mm−1 resolution by embedding Eu(II)-based scintillators into AAO film. Our results create the new family of low-dimensional rare-earth-based halides for scintillation and related optoelectronic applications.

Comprehensive investigation of [formula omitted] and [formula omitted] rare earth-based scintillation materials using density functional theory

In this paper, we investigate the structural, elastic, electronic, and optical properties of the new rare earth-based scintillation materials Rb2LuCl5 and Rb2PrCl5 using DFT calculations. The results show that both compounds are dynamically stable. Analysis of the elastic properties reveals that Rb2PrCl5 is more isotropic in its mechanical behavior, while Rb2LuCl5 exhibits a greater degree of anisotropy. Both Rb2LuCl5 and Rb2PrCl5 have direct band gaps (5.0698 and 4.7022 eV, respectively), according to electronic structure calculations. In terms of optical properties, both compounds exhibit higher transmittance and lower reflectance at lower energies. Calculated light yields show that under ideal conditions, Rb2LuCl5 can achieve a light yield of 78898 photons per MeV, while Rb2PrCl5 can reach a light yield of 85066 photons per MeV. This study provides valuable insights into the properties of these new rare earth-based scintillation materials, which can contribute to the development and optimization of improved scintillation detectors.

Deep near infrared light-excited stable synergistic photodynamic and photothermal therapies based on P-IR890 nano-photosensitizer constructed via a non-cyanine dye

The cyanine dyes represented by IR780 can achieve synergistic photodynamic therapy (PDT) and photothermal therapy (PTT) under the stimulation of near-infrared (NIR) light (commonly 808 nm). Unfortunately, the stability of NIR-excited cyanine dyes is not satisfactory. These cyanine dyes can be attacked by self-generated reactive oxygen species (ROS) during PDT processes, resulting in structural damage and rapid degradation, which is fatal for phototherapy. To address this issue, a novel non-cyanine dye (IR890) was elaborately designed and synthesized by our team. The maximum absorption wavelength of IR890 was located in the deep NIR region (ca. 890 nm), which was beneficial for further improving tissue penetration depth. Importantly, IR890 exhibited good stability when continuously illuminated by deep NIR light. To improve the hydrophilicity and biocompatibility, the hydrophobic IR890 dye was grafted onto the side chain of hydrophilic polymer (POEGMA-b-PGMA-g-CCH) via click chemistry. Then, the synthesized POEGMA-b-PGMA-g-IR890 amphiphilic polymer was utilized to prepare P-IR890 nano-photosensitizer via self-assembly method. Under irradiation with deep NIR light (850 nm, 0.5 W/cm2, 10 min), the dye degradation rate of P-IR890 was less than 5%. However, IR780 was almost completely degraded with the same light output power density and irradiation duration. In addition, P-IR890 could stably generate a large number of ROS and heat at the same time. It was rarely reported that the stable synergistic combination therapy of PDT and PTT could be efficiently performed by a single photosensitizer via irradiation with deep NIR light. P-IR890 exhibited favorable anti-tumor outcomes through apoptosis pathway. Therefore, the P-IR890 could provide a new insight into the design of photosensitizers and new opportunities for synergistic combination therapy of PDT and PTT.

Near Ultraviolet‐Excitable Cyan‐Emissive Hybrid Copper(I) Halides Nonlinear Optical Crystals with Near‐Unity Photoluminescence Quantum Yield and High‐Efficiency X‐ray Scintillation

AbstractDesigning and synthesizing multifunctional hybrid copper halides with near ultraviolet (NUV) light‐excited high‐energy emission (<500 nm) remains challenging. Here, a pair of broadband‐excited high‐energy emitting isomers, namely, α‐/β‐(MePh3P)2CuI3 (MePh3P=methyltriphenylphosphonium), were synthesized. α‐(MePh3P)2CuI3 with blue emission peaking at 475 nm is firstly discovered wherein its structure contains regular [CuI3]2− triangles and crystallizes in centrosymmetric space group P21/c. While β‐(MePh3P)2CuI3 featuring distorted [CuI3]2− planar triangles shows inversion symmetry breaking and crystallizes in the noncentrosymmetric space group P21, which exhibits cyan emission peaking at 495 nm with prominent near‐unity photoluminescence quantum yield and the excitation band ranging from 200 to 450 nm. Intriguingly, β‐(MePh3P)2CuI3 exhibits phase‐matchable second‐harmonic generation response of 0.54×KDP and a suitable birefringence of 0.06@1064 nm. Furthermore, β‐(MePh3P)2CuI3 also can be excited by X‐ray radioluminescence with a high scintillation light yield of 16193 photon/MeV and an ultra‐low detection limit of 47.97 nGy/s, which is only 0.87 % of the standard medical diagnosis (5.5 μGy/s). This work not only promotes the development of solid‐state lighting, laser frequency conversion and X‐ray imaging, but also provides a reference for constructing multifunctional hybrid metal halides.

Calibration of the sensitivity of the bibenzyl-based scintillation detector to 1–5 MeV neutrons

The neutron time-of-flight (nTOF) detector, which is based on bibenzyl, an organic crystal scintillator with low afterglow, is used to diagnose the fuel areal density of target capsules by measuring the down-scattered neutron ratio. This paper presents a method for calibrating the sensitivity of bibenzyl scintillation detectors to 1–5 MeV down-scattered neutrons. The distributions of detector sensitivity are analyzed using the Monte-Carlo method. The analysis shows that most light output of neutrons below 5 MeV comes from recoil protons. Therefore, the sensitivity of the back-scattered neutron can be calculated with the 2.45 MeV neutron sensitivity and the relative responses of the 1–5 MeV protons. These responses are calibrated using a deuterium-deuterium implosion neutron source at a 100-kJ laser facility and a monoenergetic proton beam at a Van de Graaf accelerator, respectively. The total uncertainty of the calibration for 1–5 MeV neutron sensitivity ranges from 5% to 9%. This calibration method provides accurate measurements for the broad-spectrum neutron sensitivity of scintillation detectors.

Characterization of a novel polyurethane-based plastic scintillator for neutron and gamma detection in mixed radiation fields

We present studies of a novel plastic scintillator branded M600, which was developed and provided by Target Systemelektronik. This new material is, in contrast to other solid organic scintillators offered by commercial providers, based on a polyurethane matrix complemented with scintillating and wavelength-shifting additives. This paper covers measurements of absolute light output, LO, (photons per 1 MeV-γ), γ-non-proportionality (NP), light pulse shapes, and neutron-gamma (n/γ) discrimination. The measurements were carried out either using standard calibration gamma sources (LO, NP) or in a mixed field of neutron and γ radiation from an intense (∼4 × 105 neutrons/s/4π) AmBe source (n/γ discrimination). The measured light output was 9650 ± 1000 ph/MeV and the PSD's figure of merit (FoM) was found as 2.2 ± 0.1 at ∼1000 keVee for ∅2.54 cm × 2.54 cm M600 sample. The bigger sample (∅5.08 cm × 5.08 cm) exhibits about 25% lower LO and poorer FoM when compared to the ∅2.54 cm × 2.54 cm M600, due to self-absorption.

Optimized Bridgman growth of Cs2LiYCl6:Ce single crystals and energy resolution improvement by codoping

Cs2LiYCl6:Ce is a novel scintillation crystal with good energy resolution, high light yield, and outstanding neutron/gamma discrimination capability. However, its complex composition and incongruent melting behavior pose many challenges to the crystal growth. In this study, five different compositions of Cs2LiYCl6:Ce crystals were grown using the vertical Bridgman method. These compositions included LiCl at 57 mol%, 60 mol%, and 63 mol%, as well as CsCl and YCl3 at ratios of 1.9:1 and 2.1:1. It was found that the highest CLYC phase volume fraction could be obtained in the recipe with a LiCl composition of 60 mol%, while changing the ratio of CsCl to YCl3 did not show any significant positive effect on crystal growth. In addition, Ca2+/Sr2+ was applied to modify the scintillation performance of CLYC:Ce. A batch of Φ11mm crystals with different co-doping concentrations of Ca2+ and Sr2+ were successfully grown by using the Multi-ampoule Bridgman method, no cracks or inclusions were observed in the grown crystals. Co-doping showed little effect on the radiation luminescence and transmittance spectra of CLYC. The scintillation decay curves demonstrated that the decay times depend on the co-doping concentration. Most notably, the energy resolution of CLYC:Ce is improved from 4.6 % to 3.8 % by co-doping 0.05 % Sr2+ under 662 keV gamma-ray excitation. However, the light yield is reduced because of co-doping of Ca2+ and Sr2+, especially Ca2+ having a more pronounced effect.

High quantum yield luminescence and scintillation properties of high-Ce-doped MgF2–Al2O3–B2O3 glasses and their glass structure

Ce-doped inorganic single crystals are currently used in scintillators in various instruments because of their outstanding luminescence properties. However, these crystals are expensive to manufacture and are inefficient in terms of their energy consumption. In this study, xCeF3-doped 40MgF2–20Al2O3–40B2O3 glasses (x = 0−30 mol%) were prepared by a melt-quenching method in N2 atmosphere, and their photoluminescence, scintillation, and dosimetry properties were investigated. The X-ray absorption fine edge spectroscopy of the Ce L3-edge indicated that the doped Ce exists in the form of Ce3+ ions, and that Ce4+ does not form because of the low basicity of the glass. The glasses underwent photoluminescence at 380 nm due to the 5d-4f transition of Ce3+, with a very high quantum yield of up to ∼100 % and low concentration quenching. The peak shape of the X-ray-induced luminescence was similar to that of the PL with a decay time of 110−70 ns. The light yields for gamma rays (137Cs source) were obtained from the pulse-height spectra, and the highest light yield among the present samples was 1071 photons/MeV with the energy resolution of 17 %. The thermoluminescence glow curves had peaks at 365 and 460 K and a good linear relationship existed in the range of 0.5–1000 mGy, with the dose response being comparable to that of a commercial dosimeter. The origin of the high quantum yield was probed by analyzing the glass structure using molecular dynamics simulation based on a graph neural network. A strong tendency to selectively bind cations and anion pairs was found: Mg preferably binds to F, B preferably binds to O, and Al binds to O and F, which can be explained by soft and hard acid and base theories. Because of this selectivity the glass forms fluoride- and oxide-rich domains, which seem to be responsible for the more effective dispersal of the luminescent center. The results of this study are expected to contribute to the development of glasses with enhanced photoluminescence and scintillation luminescence properties.

Efficient and Ultrafast Oxyorthosilicate Scintillator by Activator Valence State Manipulation.

There is an urgent need for faster, brighter, and more controllable scintillation materials in advanced nuclear medicine, high-energy physical experiments, and dark matter particle detection. Nevertheless, the trade-off between high emission efficiency and fast timing characteristics remains a common challenge in the entire optical field. To address this issue, we develop a composition engineering strategy that involves multisite selective doping. This strategy aims to transform nearly all Ce3+ into fast-emitting Ce4+ while synergistically suppressing the electron traps. Even at very low doping concentrations, the designed Ca2+, Al3+, and Ce3+ tridoped oxyorthosilicate exhibits a scintillation decay (τd) acceleration of 20%, accompanied by a 25% increase in light yield (LY). The ratio of emission efficiency and timing characteristics (LY/τd) can be enhanced by 56%, which realizes the perfect balance of high LY and fast τd. Our work provides a method for designing efficient, ultrafast, and controllable scintillators in multicomponent systems, thus paving the way for high-resolution radiation detection and imaging applications.

Performance comparison of flip-chip blue-light microLEDs with various passivation

In this study, arrays of μLEDs in four different sizes (5 × 5 μm2, 10 × 10 μm2, 25 × 25 μm2, 50 × 50 μm2) were fabricated using a flip-chip bonding process. Two passivation processes were investigated with one involving a single layer of SiO2 deposited using plasma-enhanced chemical vapor deposition (PECVD) and the other incorporating Al2O3 deposited by atomic layer deposition (ALD) beneath the SiO2 layer. Owing to superior coverage and protection, the double-layers passivation process resulted in a three-order lower leakage current of μLEDs in the 5 μm chip-sized μLED arrays. Furthermore, higher light output power of μLEDs was observed in each chip-sized μLED array with double layers passivation. Particularly, the highest EQE value 21.9% of μLEDs array with 5 μm × 5 μm chip size was achieved with the double-layers passivation. The EQE value of μLEDs array was improved by 4.4 times by introducing the double-layers passivation as compared with that of μLEDs array with single layer passivation. Finally, more uniform light emission patterns were observed in the μLEDs with 5 μm × 5 μm chip size fabricated by double-layer passivation process using ImageJ software.

Performance stability of plastics for neutron-gamma pulse shape discrimination

The introduction of the first commercially available plastic scintillators with pulse shape discrimination (PSD) offered by Eljen Technology marked progress towards potentially replacing liquid scintillators in neutron detection. However, use of these plastics over several recent years has revealed an important flaw in these materials: the eventual degradation of scintillation light output and PSD performance. Studies described in this paper considered possible reasons for this degradation. Experiments conducted with numerous lab-prepared and commercial EJ-276 samples showed that the main factor affecting the instability is oxidation that involves highly reactive radicals generated during the polymerization process or from the further breakdown of polymer chains under oxygen/air exposure. Based on the obtained results, the stability of scintillation performance for PPO (2,5-Diphenyloxazole)-based PSD plastics has been improved through modifications of the composition via the utilization of scintillation dyes and compounds with antioxidant properties that diminish the effects of oxidation. Elements of these studies were used in the commercial production of the most recent EJ-276D PSD plastic version for fast neutron detection and 6Li-loaded plastics for thermal neutron and antineutrino detection applications. Performance projections of the new PSD plastics indicate a likely degradation of less than 10 % over 5–10 years in comparison to previous EJ-276 that might lose up to 30–40 % of the scintillation light during 1–2 years of storage or deployment under ambient conditions.

Multi-objective scintillator shape optimization for increased photodetector light collection

Inorganic scintillators often use exotic, expensive materials to increase their light yield. Although material chemistry is a valid way to increase the light collection, these methods are expensive and limited to the material properties. As such, alternative methods such as the use of specific reflective coatings and crystal optical shapes are critical for the scintillator crystal design procedure. In this paper, we explore the modeling of a scintillator and silicon-photomultiplier (SiPM) assembly detector using GEANT4. GEANT4, an open-source software for particle–matter interaction based on ray-tracing, allows the modeling of a scintillator-based detector while offering methods to simplify and study the computational requirements for a precise calculation of the light collection. These studies incorporate two different geometries compatible with the barrel timing layer (BTL) particle detector that is being built for the compact muon solenoid (CME) experiment at CERN. Furthermore, the geometry of our model is parameterized using splines for smoother results and meshed using GMSH to perform genetic numerical optimization of the crystal shape through genetic algorithms, in particular non-dominated sorting genetic algorithm II (NGSAII). Using NSGA-II, we provide a series of optimized scintillator geometries and study the trade-offs of multiple possible objective functions including the light output, light collection, light collection per energy deposited, and track path length. The converged Pareto results according to the hypervolume indicator are compared to the original simplified design, and a recommendation towards the use of the light collection per energy deposition and track path length is given based on the results. The results provide increases in this objective of up to 18% for a constant volume for a geometry compatible with the current design of the BTL detector.

Investigation of X-rays Beams Uniformity in Radiotherapeutic Tumor Treatment Procedure Using LuAG:Ce Crystal Detectors.

In this study, Ce3+-doped Lu3Al5O12 garnet (LuAG) crystal detectors, with a density of ρ = 6 g/cm3 and an effective atomic number Zeff = 62, are proposed as promising materials for radiotherapy applications. This type of detector demonstrates excellent uniformity of structural and optical properties, high thermoluminescence (TL) light yield, optimal position of main TL glow peaks at temperatures around 245-295 °C, and high radiation stability. The set of TL detectors made from LuAG:Ce single crystal was used to evaluate the uniformity of dose and energy spectra of X-ray radiation from a clinical accelerator with 6 MV and 15 MV beams at the Department of Medical Physics, Oncology Center in Bydgoszcz, Poland, and γ-rays from a 60Co source at the National Institute of Oncology in Warsaw. The LuAG:Ce crystal detectors demonstrated highly promising results for registering X-ray radiation from accelerators with both 6 MV and 15 MV electron beams, as well as γ-rays from a 60Co source with energies of 1.17 and 1.33 MeV.

Highly efficient AlGaN-based deep-ultraviolet light-emitting diodes: from bandgap engineering to device craft

AlGaN-based light-emitting diodes (LEDs) operating in the deep-ultraviolet (DUV) spectral range (210–280 nm) have demonstrated potential applications in physical sterilization. However, the poor external quantum efficiency (EQE) hinders further advances in the emission performance of AlGaN-based DUV LEDs. Here, we demonstrate the performance of 270-nm AlGaN-based DUV LEDs beyond the state-of-the-art by exploiting the innovative combination of bandgap engineering and device craft. By adopting tailored multiple quantum wells (MQWs), a reflective Al reflector, a low-optical-loss tunneling junction (TJ) and a dielectric SiO2 insertion structure (IS-SiO2), outstanding light output powers (LOPs) of 140.1 mW are achieved in our DUV LEDs at 850 mA. The EQEs of our DUV LEDs are 4.5 times greater than those of their conventional counterparts. This comprehensive approach overcomes the major difficulties commonly faced in the pursuit of high-performance AlGaN-based DUV LEDs, such as strong quantum-confined Stark effect (QCSE), severe optical absorption in the p-electrode/ohmic contact layer and poor transverse magnetic (TM)-polarized light extraction. Furthermore, the on-wafer electroluminescence characterization validated the scalability of our DUV LEDs to larger production scales. Our work is promising for the development of highly efficient AlGaN-based DUV LEDs.

Heating revival of Cs3MnBr5 for anti-counterfeiting and large-area flexible X-ray imaging

Cesium manganese bromide metal halide has great potential in the field of X-ray imaging and anti-counterfeiting due to its excellent optoelectronic properties. Here, Cs3MnBr5 was successfully prepared by a simple method. Uniquely a novel phenomenon based on H2O induced color change was discovered, Cs3MnBr5 can recover from aqueous solution more than 10 times under heating, which can be used in fluorescent anti-counterfeiting applications. Furthermore, Cs3MnBr5@PDMS, prepared by the PDMS composite strategy, has been demonstrated to exhibit a stability that is 20 times greater than that of Cs3MnBr5. Simultaneously, the light yield of Cs3MnBr5 is evaluated to be 21688 photons/MeV. Furthermore, it has been successfully applied in non-destructive detection and biological imaging and the spatial resolution can be restored to 10 lp mm−1.

Catalytic pyrolysis of straight-run naphtha to light olefins: Experiment and molecular-level kinetic modeling study

In this work, molecular-level kinetic modeling was developed for the fluid catalytic pyrolysis of straight-run naphtha based on the structural unit and bond-electron matrix framework. The kinetic parameters were tuned and optimized using systematic experimental data from a fluidized bed under different conditions, the predicted values of the fraction yield, naphtha composition, and gas product yield were in agreement with the experimental data. The model can obtain the typical reaction rate of naphtha with different carbon numbers and structure compositions at the molecular level under typical conditions. The model can also quantify and compare the effects of eliminating different side reactions on the light olefins production, and different optimized reaction types of naphtha feedstocks under two typical conditions were revealed, quantitative model calculations show a significant boost in light olefin yield of 15–33 percentage points without hydrogen transfer.

Reliability-based Design Optimization (RBDO) Study Applied to the Thermal Management of a Multi-Led Chip Package

Solid-state lighting based on LEDs is used in various applications, including display, communications, etc. However, the high junction temperature is still challenging due to the LED chip’s reduced light output and lifetime. To face this challenge, a thermal study was done to determine junction temperature TJ of a multi-led chip package. Then, a sensitivity analysis of different materials was performed using the Sobol method to identify the parameters that most influence the junction temperature. To calculate the probability of failure of the model, the FORM-SORM and Monte Carlo methodologies were employed in this study. It was obtained that the probability of failure of the LED package is roughly 20%. An optimum design was created using reliability-based design optimization (RBDO) to lower this percentage. After application of this method, the junction temperature was lowered by 11% and the reliability level increased from 80% to 91%.