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, F-38054, Grenoble, France, LMOPS, University of Lorraine, EA4423, Metz, France

In0.16Ga0.84N/In0.05Ga0.95N Multiple Quantum Well (MQW) structure grown on a 70 nm thick high quality semi-bulk InGaN buffer layer is reported. Temperature dependent photoluminescence (PL) reveals 67.5% of room temperature Internal Quantum Efficiency (IQE) at an emission peak of ?455 nm with FWHM of 20 nm. Low temperature PL study shows clear improvement in emission intensity when conventional GaN buffer and GaN barrier are replaced by semi-bulk InGaN buffer in addition with InGaN barrier. Simulation confirms improved IQE and reduced efficiency droop when using semi-bulk as buffer which is attributed to the improved overlapping of electron-hole wave functions due to the reduced internal electric field from counteraction by surface polarization field. This efficiency improvement is very beneficial for high In content green LEDs where the efficiency is limited by polarization induced Quantum Confined Stark Effect (QCSE) for excess indium content. © 2017 Elsevier Ltd

InGaN buffer, InGaN multi-quantum-well, LED, MOVPE

Efficiency, Electric fields, Gallium nitride, Light emitting diodes, Metallorganic vapor phase epitaxy, Polarization, Quantum efficiency, Semiconducting indium compounds, Temperature, Wave functions, Efficiency improvement, InGaN buffer, Internal electric fields, Internal quantum efficiency, Multi quantum wells, Multiple quantum-well structures, Quantum-confined Stark effect, Temperature dependent photoluminescences, Semiconductor quantum wells