High efficiency InGaN nanowire tunnel junction green micro-LEDs
Xianhe Liu, Yi Sun, Yakshita Malhotra, Ayush Pandey, Yuanpeng Wu, Kai Sun, Zetian Mi
Abstract
We report on the study of InGaN nanowire green light emitting diodes (LEDs) with lateral dimensions varying from ∼1 to 10 μm. For a device with an areal size ∼3 × 3 μm2, a maximum external quantum efficiency ∼5.5% was directly measured on wafer without any packaging. The efficiency peaks at ∼3.4 A/cm2 and exhibits ∼30% drop at an injection current density ∼28 A/cm2. Detailed analysis further suggests that a maximum external quantum efficiency in the range of 30%–90% can potentially be achieved for InGaN nanowire micro-LEDs by optimizing the light extraction efficiency, reducing point defect formation, and controlling electron overflow. This study offers a viable path for achieving ultrahigh efficiency micro-LEDs operating in the visible.