A. E. Chernyakov

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Unpredictable fast failure of blue power InGaN/GaN LEDs is caused by redistribution of In under action of injection currents between nano-scale regions of InGaN alloy with non-equilibrium composition. Unreliable LEDs can be recognized by the increase in forward current values at U < 2 V which is not accompanied by simultaneous reversed current increase(More)
Current spreading in a high-power flip-chip light-emitting diode (LED) and its effect on the chip thermal resistance has been studied both theoretically and experimentally. Thermal resistances of various LED units have been determined by measuring the forward voltage relaxation under pulsed current excitation of the LED at varied duty cycle. The total(More)
Analysis of the thermal resistance of power light-emitting diodes (LEDs) of Cree and Rebel types is developed. Components of the thermal resistance of the diodes are determined and several distinguishes between different methods are obtained. Behavior of bottleneck effect related to definite interfaces is established. The value of LED active junction area(More)
Analysis of the thermal resistance of power light-emitting diodes (LEDs) of Cree types is performed. Components of the thermal resistance of the diodes are determined and several distinguishes between different methods are obtained. Behavior of bottleneck effect related to definite interfaces is established. The value of LED active junction area is(More)
The paper reports on influence of the emission wavelength on characteristics and performance of high-power light-emitting diodes (LEDs) emitting light in the near-UV (370 nm) and green (530 nm) spectral ranges and having a similar chip design. Similarity and difference in operation of the LEDs is revealed by their detailed characterization. The correlations(More)
The results of the degradation study of commercial InGaN/GaN LEDs with the external quantum efficiency (EQE) ~ 40-50 % at 450-460 nm are presented. It has been clarified that one of the mechanisms responsible for EQE degradation and the unpredictable failure of LEDs is the multiphonon recombination of carriers. The distorted forward branch of I-V(More)
The driving current, chip area of high-power AlGaInN light emitting diodes (LEDs) and the level of integration of LED arrays are continuously increased to provide ever higher output light flux. The new developments require more attention to pay to the thermal management of LEDs, commonly assessed in terms of the thermal resistance. Temperature distribution(More)
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