Influence of AlGaN Electron Blocking Layer on Modulation Bandwidth of GaN-Based Light Emitting Diodes

GaN-based LEDs is applied to illumination and visible-light communication. In this study, we research the impact of electron blocking layer (EBL) with different aluminum (Al) contents of 20% and 15% on the modulation bandwidth of high-power LEDs. LEDs with 15% Al in EBL shows higher radiative recombination rate and hole injection efficiency. Moreover, LED with 15% Al in EBL exhibits the modulation bandwidth of 25.5 MHz versus 23.5 MHz for LED with 20% Al at 300 mA. This finding demonstrates the influence of piezoelectric polarization field and low hole injection efficiency caused by EBL on modulation bandwidth of high-power LEDs. (C) 2014 The Electrochemical Society. All rights reserved.