GaN-Based LEDs With a Chirped Multiquantum Barrier Structure

We report the fabrication of GaN-based blue light-emitting diodes (LEDs), which separately incorporate the three different electron blocking layers (EBLs), namely, a conventional AlGaN, a uniform multiquantum barrier (UMQB), and a chirped multiquantum barrier (CMQB). On the administration of 20 mA injection current, the corresponding LED output powers measured were 27.5, 27.2, and 25.4 mW for CMQB LED, UMQB LED, and LED, respectively, with a conventional AlGaN EBL. It was also found that the LED with CMQB EBL exhibited a significantly lower drooping effect and a smaller forward bias as compared with LEDs with a conventional AlGaN EBL and UMQB EBL.