School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, United States, Georgia Tech-CNRS, UMI 2958, Metz, France, CEA-LETI, Minatec Campus, Grenoble, France, LMOPS, University of Lorraine, EA4423, Metz, France

The effect of indium (In) in the barrier of InGaN/GaN multiple quantum well (MQW) has been studied for MQWs with and without semi-bulk InGaN buffer. From simulation, the optimum In content in the barrier with 3–5 nm width is 5–7% to get the optimal material quality and internal quantum efficiency (IQE) of ?65% for 450–480 nm emission range. Simulation shows a reduction of the potential barrier due to band flattening, a more homogeneous distribution of electrons and holes in the active region and subsequently, a more radiative recombination rate with InGaN as barrier layer. Both cathodoluminescence (CL) and photoluminescence (PL) experimental results show a blue-shift of emission wavelength along with an enhancement in the emission intensity when GaN barrier is replaced with InGaN barrier, for a MQW structure both with and without the semi-bulk InGaN buffer. We attribute this blue shift to the reduced polarization mismatch and increased effective bandgap. This InGaN barrier-related improvement in IQE and efficiency droop could be useful for the realization of longer wavelength “green-gap” range LEDs where poor IQE and efficiency droop are more prominent due to high indium (In) in the active region. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

barrier layer, III-nitride semiconductors, InGaN, light-emitting diodes, MOVPE, multiple quantum well

Efficiency, Indium, Light emitting diodes, Metallorganic vapor phase epitaxy, Quantum efficiency, Semiconducting indium compounds, Barrier layers, Electrons and holes, Emission wavelength, Homogeneous distribution, III-nitride semiconductors, InGaN, Internal quantum efficiency, Radiative recombination rate, Semiconductor quantum wells