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The built-in electric field in an InGaN quantum well and emission wavelength are numerically evaluated at various GaN barrier thicknesses in blue InGaN/GaN/Al 2 O 3 LED structures. The effect of GaN barrier thickness on the internal quantum efficiency of these structures was studied experimentally by temperature-and excitation-power-dependent photoluminescence measurements. In LED structures with 3-nm-thick GaN barriers in the active region the internal quantum efficiency at high excitation levels higher than that in LED structures with thicker GaN barriers. The results of measurements indicate that in structures with 3-nm-thick GaN barriers, the Auger recombination rate is reduced.

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The results of experimental studies of forward current-voltage characteristics of LEDs with an active region consisting of the multiple (Al x Ga 1-x ) 0.5 In 0.5 P/(Al 0.54 Ga 0.46 ) 0.5 In 0.5 P quantum wells are presented. The experiment showed that increasing the number of quantum wells and decreasing the Al content in the Al x Ga 1-x solid solution lead to an increase in the forward current at a fixed voltage. An analysis showed that the results obtained can be interpreted using the theory of diffusion charge transport in a double heterostructure with a narrow-bandgap layer, the thickness of which is many times larger than the thickness of a single quantum well. The proposed approach takes into account the carrier transport by tunneling through the barriers in an active region with multiple quantum wells.

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