GaN-Based LED with Embedded Microlens-like Structure

By depositing two pairs of GaN/AlGaN on the template with GaN mu-pillars, we successfully realized an embedded microlens-like structure by metallorganic chemical vapor deposition. With the structure, we achieved a smaller electroluminescence linewidth and a smaller reverse leakage current due to the lateral growth induced crystal quality improvement. With the device size of 250 X 575 mu m and an output wavelength of 455 nm, the 20 mA output power of the light emitting diode (LED) without and with the embedded microlens-like structure was 3.97 and 5.20 mW, respectively. From the ray tracing simulation, the embedded microlens-like GaN/AlGaN multilayer would serve as the light scattering center inside the LED and enhanced the light output power. (C) 2009 The Electrochemical Society. [DOI: 10.1149/1.3243879]