Light-emitting Diode Chip Research Articles

Self-protective GaInN-based light-emitting diodes with VO2 nanowires.

We presented a new functional GaInN-based light-emitting diode (LED) that is capable of protecting itself from unwanted thermal damage (a so-called self-protective LED). This functionality was achieved by incorporating VO2 nanowires on the LED chip. VO2 nanowires, as metal-insulator transition materials, show a phase transition from insulating to metallic at a characteristic transition temperature. By placing a VO2 nanowire between the n- and p-contacts of an LED, a parallel circuit was formed with the existing diode. As the VO2 nanowire became metal-like at its characteristic temperature, it induced a short-circuit state in the device, protecting the LED from heat damage at elevated temperatures. Details on the self-protective LED were elucidated, from a conceptual description to experimental proof.

Effect of particle sizes and mass ratios of a phosphor on light color performance of a green phosphor thin film and a laminated white light-emitting diode.

Green phosphor thin films with different silica resin/phosphor mass ratios and phosphor particle sizes were prepared by the hot pressing method. A 405 nm near-ultraviolet light-emitting diode (LED) chip was used to package the laminated white LED (WLED), and the correlated color temperature, luminous efficiency of radiation, light color uniformity, and color coordinate of the laminated WLED were obtained. An increase in the mass ratio and decrease in particle size can effectively affect the scattering coefficient of phosphor photons and the efficiency of the absorption–excitation–emission process, increasing the efficiency and light color uniformity of phosphor thin films and laminated WLEDs. By comprehensive evaluation of various light color parameters, a laminate was prepared with a mass ratio of silica resin/phosphor = 6 : 0.75, and the optimum value of the WLED was obtained. According to the IES TM30 standard, its Rf reached 92, Rg reached 101, and Rg and color distortion icons showed increased saturation for green color. Its luminous efficiency of radiation value of 270.21 lm W−1, correlated color temperature of 4423 K, and neutral white characteristics indicate that it is a device suitable for lighting applications.

Temperature dependence of the color rendering index of a phosphor-conversion white light-emitting diode

We experimentally investigated the temperature dependence of the color rendering index (CRI) of a phosphor-conversion (PC) white light-emitting diode (LED) composed of a GaN-based blue LED chip and yttrium aluminum garnet doped with Ce3+ (YAG) phosphor. For the 15 CRI values from R1 to R15, 12 CRI values were found to increase with temperature from 20 to 80 °C. The general CRI (Ra) was increased from 84.6 to 86.1 as the temperature increased from 20 to 80 °C. R9 which represents the color rendering property for the deep red was found to increase by more than 10% and some CRI values exhibited more than 20% increase in this temperature range. This increasing behavior of CRI with temperature is contrary to the case of a multi-chip-based white LED, where the Ra was reported to decrease with increasing temperature. The improvement in the CRI with temperature for the PC white LED is attributed to the relative increase of the spectral power distribution (SPD) in the wavelength range from 460 to 520 nm and the overall broadening of SPD with increasing temperature. As a result of the increase in the CRI with temperature, the PC white LEDs are expected to be advantageously used for stable high-temperature operation of LED lighting.

Investigation on Modulation Speed of Photon-Recycling White Light-Emitting Diodes With Vertical-Conduction Structure

The speed performance of a high lumen and high color rendering index (CRI) gallium nitride-based white-light light-emitting diode (LED) has been investigated in detail by measuring its electrical-to-optical frequency responses with different color filters at the receiver end. The ultra-violet/blue/green multiple quantum wells (MQWs) are stacked in the studied LED chips, which have a vertical conducting structure and red phosphor coating for generating white light with high CRI. The typical studied LED exhibits a smaller 3 dB bandwidth (0.6 MHz versus 2 MHz) compared with a reference LED with ultra-violet/blue MQWs and a yellow phosphor coating. This finding suggests that the fluorescent decay time of red phosphor is much longer than that of yellow ones (approximately 270 ns versus approximately 80 ns). In addition, the extracted carrier lifetime inside blue/green InxGa1-xN/GaN MQWs under UV light pumping/modulation is as long as approximately 50 ns, which is much slower than that of forward-biased current modulation (approximately 50 ns versus on–off keying modulation scheme are demonstrated under a moderate operation bias current (approximately 0.75 A) of studied LEDs.

Semiconductor yellow light-emitting diodes

The development of semiconductor light-emitting diode (LED) in the visible emission range is very unbalance, as the power efficiency of yellow LED is far below other colors. Based on the GaN/Si technology, the authors and his team made a systematic research from the aspect of material growth, chip fabrication, device physics and equipment design, resolved the problems of epi-film cracking, high dislocation density, large strain in quantum well (QW), phase separation in QW, low QW growth temperature, low hole concentration, light absorption by substrate and light blocking by electrode, successfully made a breakthrough in fabricating efficient yellow LED. The yellow LED chip achieves a power efficiency of 26.7% at 20 A/cm<sup>2</sup> with 565 nm wavelength and efficacy of 164 lm/W, and the power efficiency goes up to 42.8% at 1 A/cm<sup>2</sup> with 577 nm wavelength and efficacy of 248 lm/W. New LED light source with multi-colors and without phosphor was developed based on the efficient yellow LEDs, opened up a new direction of pure LED healthy lighting.

Mn4+-activated BaLaMgSbO6 double-perovskite phosphor: a novel high-efficiency far-red-emitting luminescent material for indoor plant growth lighting.

In the present work, novel high-efficiency Mn4+-activated BaLaMgSbO6 (BLMS) far-red-emitting phosphors used for plant growth LEDs were successfully synthesized via a solid-state reaction method. X-ray diffraction (XRD), photoluminescence (PL), temperature-dependent PL, CIE color coordinates, and lifetimes as well as internal quantum efficiency (IQE) were used to characterize the phosphor samples. The excitation spectrum of the as-obtained BLMS:Mn4+ phosphors presented two wide bands covering 250–550 nm and the emission spectrum exhibited a far-red emission band in the range of 650–800 nm peaked at 700 nm. Concentration-dependent PL properties of BLMS:Mn4+ phosphors were studied. The optimal doping concentration of Mn4+ ions was 0.6 mol%, and the concentration quenching mechanism was determined to be the nonradiative energy transfer among the nearest-neighbor Mn4+ activators. Impressively, the BLMS:0.6%Mn4+ sample showed an outstanding IQE of 83%. In addition, luminescence thermal quenching characteristics were also analyzed. Furthermore, the PL spectrum of BLMS:0.6%Mn4+ sample was compared with the absorption spectrum of phytochrome PFR. Finally, after combining BLMS:0.6%Mn4+ phosphors with a 365 nm near-UV LED chip, a far-red light-emitting diode (LED) device was successfully achieved to demonstrate its possible applications in plant growth LEDs.

Red-emitting phosphor Na2Ca2Nb4O13:Eu3+ for LEDs: Synthesis and luminescence properties

Na2Ca2Nb4O13:Eu3+ phosphor is successfully synthesize by the high-temperature solid-state reaction method in air. The crystal structures, morphology, X-ray powder diffractions (XRPD) patterns, energy dispersive X-ray (EDX) spectrum, decay curves, and luminescence properties are investigated. Na2Ca2Nb4O13:Eu3+ phosphor emits red light with the chromaticity coordinates (0.6312, 0.3684) and the emission spectrum is observed in the range of 575–725 nm, which contains four emission bands because of the 5D0 → 7F1 (575–600 nm), 5D0 → 7F2 (600–650 nm), 5D0 → 7F3 (650–670 nm), 5D0 → 7F4 (680–725 nm) transitions of Eu3+ ion, respectively. The optimal Eu3+ ion concentration in Na2Ca2Nb4O13:Eu3+ phosphor is ~10 mol%. The lifetime decreases in turn from 736.5 μs to 431.8 μs with increasing Eu3+ ion concentration from 2 mol% to 12 mol%. Na2Ca2Nb4O13:Eu3+ phosphor has a good thermal stability according to the temperature-dependent emission spectra. Luminous mechanism is explained by energy level diagram of Eu3+ ion. The experimental results indicate that Na2Ca2Nb4O13:Eu3+ phosphor has a hope to be used as red phosphor for light-emitting diodes (LEDs) based on near ultraviolet (UV) and blue LED chips.

Broadband near-ultraviolet excited La2Mo2O9:Eu3+ red-emitting phosphors with high color purity for solid-state lighting

A series of different Eu3+ ions incorporated La2Mo2O9 phosphors exhibiting photoluminescence (PL) peaks in the red region (613 nm; 5D0→7F2) were successfully synthesized by a citrate sol-gel method. Under the 351 nm excitation, the optimal doping concentration of Eu3+ ions was identified to be 25 mol% with higher PL emission intensity and further the concentration quenching mechanism was governed by electric diploe-diploe interaction. More importantly, the optimized phosphor was demonstrated high color purity while the Commission Internationale de I'Eclairage chromaticity coordinates were (0.661, 0.339). The intrinsic radiative transition lifetime for the optimized red phosphor was calculated to be 530.7 μs and the local structure environment of Eu3+ ions in the La2Mo2O9 host matrix was also analyzed by the Judd-Ofelt theory. Moreover, a red-emitting light-emitting diode (LED) device was fabricated by combing a near-ultraviolet LED chip with the optimized red phosphor, which exhibits a dazzling red light. Based on the obtained results, the Eu3+ ions activated La2Mo2O9 phosphors are expected to be as a promising red-emitting phosphor for solid-state lighting.

Comparison of the Changes in Luminescence Properties Between Cool White and Warm White LEDs at Varying Temperatures

The changes of luminescence properties in cool white (CW) and warm white (WW) light-emitting diodes (LEDs) in response to operating temperatures are compared in this paper. In addition, the emission spectrum of blue LED chips was characterized under the same experimental conditions for cross-reference analysis. The yellow YAG (Y3Al5O12:Ce <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> ) and red nitrididosilicate (Sr2Si5N8:Eu <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2+</sup> ) phosphors were synthesized in-house and packed at different concentration configurations to create LED samples of correlated color temperature 6500 K for CW LEDs and 2700 K for WW LEDs. The emission spectrum measurements showed drastic decrements of light emission intensities for both CW and WW LED samples at elevated temperature. Both CW and WW LED samples tend to have more bluish hue with increasing temperatures. Furthermore, the trend of color rendering index (CRI) changes of CW and WW LEDs has differed, a finding that is not commonly reported in other studies. The CRI of CW LED samples increased, whereas the CRI of WW LED samples decreased at elevated temperature. This is due to different shift directions of peak emission wavelength in yellow Y3Al5O12:Ce <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> and red Sr2Si5N8:Eu <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2+</sup> phosphors.

Reliability improvement of pad-extended on chip light-emitting diodes using an ultra-thin passivation layer

The pad-extended on chip (PEC) light-emitting diodes (LEDs) were fabricated and characterized by using an ultra-thin silicon oxide (SiO2) film as a passivation layer. The SiO2 thin film was deposited on the GaN mesa edge using plasma-enhanced chemical vapor deposition (PECVD) by varying deposition temperature from 150 to 350 °C. Atomic force microscopy (AFM), a scanning electron microscope (SEM) and leakage current were employed to analyze the influence of deposition temperature on the structural properties of SiO2 films. AFM measurements demonstrate that the SiO2 surface roughness was larger at a lower deposition temperature than a higher temperature. Forward voltage (Vf) characteristics of these PEC LEDs were detected and recorded for continuous ten thousand probe times. The curve of Vf remained stable at temperatures of 150, 200 and 250 °C. A metal-insulator-metal structure using 250 °C-deposited SiO2 as the dielectric indicates the leakage current density was close to 10−8 A cm−2 with the minimum one lower than 10−12 A cm−2. The relative dielectric constant of the SiO2 (20 nm) was 3.65. The ultra-thin SiO2 film efficiently passivated the GaN mesa edge and prevented charge accumulation at the surface. Reliability has been improved for PEC LEDs using the ultra-thin SiO2 film as a passivation layer.

Fabrication and optical properties of divalent Cu2+ ions incorporated Ce:YAG transparent ceramics for white LEDs

Transparent Ce:YAG ceramics via Cu2+ incorporating annealed at 1450 °C were successfully fabricated by the solid-state method to probe their potential applications in white light-emitting diodes (LEDs). The influence of Cu2+ concentration on the microstructure and optical properties of the Ce:YAG transparent ceramics were systematically investigated. The as-prepared ceramics possessed clean grain boundaries and homogeneous grain size distribution ranging from 3.7 to 6.5 µm. With the addition amount of Cu2+ increased, the red component of ceramics gradually increased and then decreased, it reached a maximum of 13.0% at 1.5 at% Cu2+ incorporation. By combining with commercially blue LED chips (465 nm) directly, the obtained optimal chromaticity coordinates (CIE) and correlated color temperature (CCT) of ceramics were (x = 0.3335, y = 0.3412) and 5450 K, respectively, while its color render index (CRI) was nearly 70 at the thickness of 1.0 mm. Therefore, this study provided an efficient approach to tailor the luminescence property of Ce:YAG ceramic for white LEDs.

Lifetime prediction of a multi-chip high-power LED light source based on artificial neural networks

A high power light-emitting diodes (LED) light source, which is assembled by many LED chips and heat sink, has a not uniform temperature distribution at working condition. Analysis and prediction of a high-power LED system lifetime are complicated and time-consuming. In this study, two artificial neural networks (ANN) are employed to simplify the LED lighting system’s lifetime prediction and increase the precision of such analysis. The temperature distribution of the high power light source is calculated by Finite element method (FEM) with LED chip photo-electro-thermal (PET) ANN. With the precise LED temperature distribution, the lifetime for multi-chip high-power LED light source can be predicted by lifetime ANN. The PET ANN is used to simplify the multi-physics coupling in LED PET analyzing. The lifetime ANN can predict the lifetime of a LED chip across a wide range of temperatures and not merely corresponding to several testing and interpolation points. This work aims to rapidly analyze multi-chip high-power lighting systems characteristics. The repeated tests and calculations of PET and lifetime are avoided with this method. This approach presents a new and effective way to assess the reliability of high-power LED light source.

Layered Structure Produced Nonconcentration Quenching in a Novel Eu3+-Doped Phosphor

Energy migration (energy transfer among identical luminescence centers) is always thought to be related to the concentration quenching in luminescence materials. However, the novel Eu3+-doped Ba6Gd2Ti4O17 phosphor seems to be an exception. In the series of Ba6Gd2(1- x)Ti4O17: xEu3+ ( x = 0.1, 0.3, 0.5, 0.7, and 0.9) phosphors prepared and investigated, no concentration quenching is found. Detailed investigations of the crystal structure and the luminescence properties of Ba6Gd2(1- x)Ti4O17: xEu3+ reveal that the nonoccurrence of concentration quenching is related to the dimensional restriction of energy migration inside the crystal lattices. In Ba6Gd2Ti4O17, directly increasing the number of Eu3+ ions to absorb as much excitation energy as possible allows to achieve a higher brightness. The highly Eu3+-doped Ba6Gd2(1- x)Ti4O17: xEu3+ ( x = 0.9) sample can convert near-UV excitation into red light, whose Commission Internationale de l'Eclairage (CIE) coordinates are (0.64, 0.36) and the color purity can reach up to 94.4%. Moreover, warm white light with the CIE chromaticity coordinates of (0.39, 0.39), the correlated color temperature of 3756 K, and the color rendering index of 82.2 is successfully generated by fabricating this highly Eu3+-doped phosphor in a near-UV light-emitting diode chip together with the green YGAB:Tb3+ and blue BAM:Eu2+ phosphors.

Highly transparent preimidized semi-alicyclic polyimide varnishes with low curing temperatures and desirable processing viscosities at high solid contents: preparation and applications for LED chip passivation

A series of semi-alicyclic polyimide (PI) resins with the number average molecular weights (Mn) in the range of 34901–74790 g/mol were prepared from a hydrogenated 3,3′,4,4′-biphenyltetracarboxylic dianhydride (HBPDA) and various aromatic diamines by a high-temperature polycondensation procedure. For comparison, the analogous PI reference resins were prepared from hydrogenated 1,2,4,5-pyromellitic dianhydride (HPMDA) and the same aromatic diamines. The prepared PI resins were all soluble in polar aprotic solvents, such as N-methyl-pyrrolidinone (NMP) and N,N-dimethylacetamide (DMAc). Various PI varnishes with the solid contents as high as 35–45 wt% were successfully prepared by dissolving the PI resins in NMP. Some of the PI varnishes, including PI-3 derived from HBPDA and 1,3-bis(3-aminophenoxy)benzene (133APB), PI-5 from HBPDA and 2,2′-bis(trifluoromethyl)benzidine (TFMB), and PI-3′ from HPMDA and 133APB exhibited desirable processing viscosities at high solid contents. For example, when the solid content was 35 wt%, the PI varnishes showed absolute viscosities of 2144 mPa s for PI-3, 9971 mPa s for PI-5, and 3156 mPa s for PI-3′, respectively. The values were 6877 mPa s for PI-3, 42370 mPa s for PI-5, and 13700 mPa s for PI-3′, respectively when the solid contents of the PI varnishes increased to 40 wt%. This unique feature made the current PI varnishes good candidates as thick-film passivation layers for chip protection. Bare light emitting diodes chips were successfully passivated via once coating by using PI-5 (HBPDA–TFMB) varnish with a solid content of 35 wt%. The HBPDA–PI passivation layers exhibited good thermal stabilities with the glass transition temperatures (Tg) in the range of 171.5–296.3 °C and 5% weight loss temperatures higher than 470 °C. In addition, they showed good optical transparency with the transmittance higher than 72% at 450 nm at a thickness of 25 µm and low yellow indices and haze values.

Hybrid White Light-Emitting Diodes Utilizing Radiative or Nonradiative Energy Transfer for Wavelength Conversion

Hybrid light-emitting diodes (LEDs) were fabricated by spin coating poly(9,9-dioctylfluorene-alt-benzothiadiazole) (F8BT) on blue InGaN/GaN multiple-quantum-well (MQW) LED chips as a downconverter. As the F8BT film thickness was in the range of 235–290 nm, the hybrid LEDs emitted cool white light with a downconversion efficiency of 28.8%. The F8BT film quality was markedly improved by postannealing at 200 °C, raising the downconversion efficiency to 82.6%. To obtain more efficient white light emission, we proposed to insert Ag nanoparticles (NPs) with a diameter of 13 nm at the inorganic–organic interface to form an MQWs/NPs/F8BT structure. Simulations showed that nonradiative energy transfer from the MQWs to F8BT can be mediated by localized surface plasmons, leading to more efficient downconversion and overall white light emission. The proof of concept of such a hybrid LED will pave the way toward high-performance phosphor-free white LED sources for microdisplay and general lighting applications.

A Comparative Study on the Junction Temperature Measurements of LEDs With Raman Spectroscopy, Microinfrared (IR) Imaging, and Forward Voltage Methods

Energy efficiency, long life, exceptional color, and performance of solid-state light sources have resulted in a rapidly increasing trend in a number of practical applications especially for general lighting after a long history of incandescent lamps. Besides, light-emitting diodes (LEDs) have thermal limitations that are vital for device quality and lifetime. Specifically, to improve the heat dissipation, one major parameter used to evaluate the LED performance is thermal resistance ( $R$ ). Reducing the resistance can improve the heat flow from the p-n junction to ambient during operation. To quantify this parameter, the LED junction temperature ( $T_{J}$ ) must be determined. In this paper, the junction temperatures are first measured with forward voltage method (FVM), Raman spectroscopy, and infrared (IR) imaging for a 465-nm bare blue LED chip (without any phosphor coating). Then, the same samples have been coated with a phosphor-particles added epoxy mixture (%13, 4300 CCT) to convert blue to white light, and the junction temperatures were measured again experimentally with the previously mentioned three methods and compared to each other. While IR imaging shows better capability on capturing the possible hotspots over the surface, Raman method and FVM were in reasonably good agreement on measuring the junction temperature for 465-nm blue (uncoated) LED chip. However, the measurements performed after coating have shown slightly different results with IR imaging and Raman methods, while FVM has shown consistent results for coated chips.

Analysis of the stiffness sensitivity of a sorting arm mechanism based on a generalized modal mass distributing matrix

A light-emitting diode chip sorting machine, which operates at high frequencies, exhibits reciprocating motion with multiple degrees of freedom and is characterized by quick starts and stops over a short range at a high frequency. The stiffness sensitivity of the chip sorter directly influences the positional accuracy of the sorting arm. However, existing experimental modal analysis methods cannot effectively identify the structural stiffness sensitivity under high-speed operation conditions. In this article, a method based on the modal mass distribution matrix is used to analyze the stiffness sensitivity of the sorting arm system. This method retrieves the modal parameters by modal analysis, after which the modal mass distribution matrix is obtained. The size of each element in the column of the matrix represents the energy distribution and stiffness sensitivity of the system under the mode. The stiffness-sensitive components of the sorting arm machine are accurately and quickly identified, thereby providing the guiding principle and basis for the dynamic optimization of the sorting arm mechanism.

Mechanism for Forming Quantum-Size AlGaN/GaN/InGaN/GaN Heterostructure Layers

The use of silicon in optoelectronic elements and microwave devices is limited by its electrical properties. In this range of application, silicon is replaced by wider-gap materials, e.g., GaN, AlN, InN, and solid solutions based on them. This allows highly efficient devices, including light-emitting diodes and photodetectors operating in a wide radiation spectral range, to be fabricated. In addition, GaN-based materials have been successfully used in designing high-power microwave devices, in particular, transistors with highly mobile electrons operating at high temperatures. We discuss specific features of the technology for fabricating active layers in the AlGaN/GaN/InGaN/GaN heterostructures with the use of metalorganic compounds. The initial substances used are ultra-pure ammonia NH3 and gallium, aluminum, and indium metalorganic compounds in the trimethyl form. The temperature dependence of the epitaxial GaN layer growth rate is investigated. This dependence is shown to be weak in a wide temperature range. The importance of adsorption processes occurring on the growth surfaces is confirmed. Thermodynamical analysis of the regularities of the investigated process is carried out to simulate the process and establish the conditions for forming GaN-based solid solutions. It is shown that during the formation of Ga1 – xInxN solid solutions in the high-temperature region the attainable InN content is not higher than 0.4 mole fractions. As the growth temperature decreases to 600°С, the conditions for incorporating In in the solid solution are noticeably improved and the InN concentration increases to 0.9 mole fractions. It is demonstrated that growing the GaAlN solid solutions in a wide temperature range makes it possible to obtain the AlN content ranging from 0.1 to 0.9 mole fractions. The experimental investigations are confirmed by the calculations. Therefore, when growing the Ga1 – xInxN quantum well layers in the active heterostructural area for commercial blue light-emitting diode chips with an indium content of х = 0.1–0.15, the growth temperature should be reduced. At low temperatures, however, it is difficult to grow epitaxial layers with a high crystal quality.

Ce3+-activated CaSr2Al2O6 green-emitting phosphors: Potential application as color converter for warm WLEDs

In this work, green-emitting Ce3+-activated CaSr2Al2O6 (CSA) phosphors were successfully synthesized by solid-state reaction at high temperature and their phase purity, crystal structure, morphologies, photoluminescence properties, as well as the thermal stability were also investigated at length. The CSA:Ce3+ phosphors exhibited an intense broad green emission band in the 450–650 nm range centered at 545 nm under 375 nm near-ultraviolet light excitation. The full width at half maximum was about 94 nm. And the optimal doping concentration of Ce3+ ions in Ca1-xSr2Al2O6:xCe3+ was x = 0.01 (namely, 1 mol%). The CIE chromaticity coordinates of CSA:0.01Ce3+ samples were calculated to be (0.3553, 0.5541) with the corresponding internal quantum efficiency determined to be about 31%. Besides, the CSA:0.01Ce3+ phosphors possessed a high thermal stability. The green emission showed slight blue-shift at high-temperature, while its emission intensity at 423 K still maintained 71.3% of the initial value at 303 K. A prototype white light-emitting-diode (LED) lamp with a superb color rendering index (CRI = 92) and a low correlated color temperature (CCT = 3671 K) was successfully fabricated by combining a 365 nm near-ultraviolet-emitting LED chip with the CSA:0.01Ce3+ as a green component, BaMgAl10O17:Eu2+ as a blue component, and CaAlSiN3:Eu2+ as a red component.

Experimental of ultra-high-power multichip COB LED

In solid-state COB (chip on board) LED (light-emitting diode), the process technology is enhanced, brightness of light per power is improved, and optical performance is increased. However, the COB LED chip junction temperature, Tj, is still a disadvantage in critically high hot spots and high temperatures. These disadvantages can shorten life and reduce efficiency. Therefore, Tj must also be solved. From a single-crystal silicon chip packaging LED to multichip COB packaging LED, this tool has become the most mainstream item in the market development of high brightness. Therefore, investigating the research approach and techniques needed to solve the high temperature Tj is necessary. In this study, the system can be used an environment-friendly refrigerant as R407C and R134a systems for a thermal cooling temperature and constant flow compression refrigeration cycle system that cool ultra-high-power multichip COB and high-brightness gallium indium nitride LED heat source. To reduce the COB LED chip, Tj, temperature needs to reach the following specifications: < 125 °C to maximum 150 °C and Tcase < 50 °C to maximum 85 °C. This temperature will maintain good luminous efficiency and long life. In addition, this approach aims to solve the maximum power of thermal dissipation Tj.