Effect of Stair-Case Electron Blocking Layer on the Performance of Blue InGaN Based LEDs

Staircase electron blocking layer (EBL) is incorporated in InGaN-based blue light-emitting diodes to numerically investigate the efficiency droop mechanism by using the APSYS simulation software. It is found that gradually reducing aluminum (Al) composition in the growth direction of the AlGaN staircase EBL can improve light output power, lower current leakage, and efficiency droop. To the contrary, increasing the Al composition in the staircase EBL along the growth direction will aggravate the electron leakage and efficiency droop. These distinct features are attributed mainly to discrepancy energy band tailoring in the EBL region, and finally different electron blocking efficiency.