Temperature dependence of electroluminescence (EL) spectral intensity of the super-bright green and blue InGaN single-quantum-well (SQW) light-emitting diodes has been studied over a wide temperature range (T=15–300 K) under a weak injection current of 0.1 mA. It is found that when T is slightly decreased to 140 K, the EL intensity efficiently increases, as usually seen due to the improved quantum efficiency. However, with further decrease of T down to 15 K, it drastically decreases due to reduced carrier capture by SQW and trapping by nonradiative recombination centers. This unusual temperature-dependent evolution of the EL intensity shows a striking difference between green and blue SQW diodes owing to the different potential depths of the InGaN well. The importance of efficient carrier capture processes by localized tail states within the SQW is thus pointed out for enhancement of radiative recombination of injected carriers in the presence of the high-density dislocations.

Temperature and injection current dependence of electroluminescence (EL) spectral intensity of the superbright green and blue InGaN single-quantum-well (SQW) light-emitting diodes has been studied over a wide temperature range (T=15−300 K) and as a function of injection current level (0.1–10 mA). It is found that, when temperature is slightly decreased to 140 K, the EL intensity efficiently increases in both cases, as usually seen due to the improved quantum efficiency. However, with further decrease of temperature down to 15 K, unusual reduction of the EL intensity is commonly observed for both of the two diodes. At low temperatures the integrated EL intensity shows a clear trend of saturation with current, accompanying decreases of the EL differential quantum efficiency. We attribute the EL reduction due to trapping of injected carriers by nonradiative recombination centers. Its dependence on temperature and current shows a striking difference between the green and blue SQW diodes. That is, we find that the blue InGaN SQW diode with a smaller In concentration shows more drastic reduction of the EL intensity at lower temperatures and at higher currents than the green one. This unusual evolution of the EL intensity with temperature and current is due to less efficient carrier capturing by SQW. The carrier capture in the green and blue diodes also shows a keen difference owing to the different In content in the InGaN well. These results are analyzed within a context of rate equation model, assuming a finite number of radiative recombination centers. Importance of the efficient carrier capture processes by localized tail states within SQW at 180–300 K is thus pointed out for explaining the observed enhancement of radiative recombination of injected carriers in the presence of high-density misfit dislocations.

Temperature and injection current dependence of electroluminescence (EL) spectral intensity of the super‐bright InGaN single‐quantum‐well (SQW) light‐emitting diodes (LEDs) has been carefully investigated over a wide temperature range (T = 15–300 K) and as a function of injection current level (0.1–10 mA). It is found that, when T is slightly decreased from 300 to 140 K, the EL intensity efficiently increases due to reduced non‐radiative recombination processes. However, with further decrease of T below 100 K, it drastically decreases due to the reduced carrier capturing by the localized radiative recombination centers and shows a clear trend of saturation with current, accompanying decreases of the EL differential efficiency. These results are analyzed based on a rate equation model, assuming a finite number of radiative recombination centers.

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