Fabrication and characterization of high efficiency green nanopillar LED

InGaN/GaN green multiple quantum well (MQW) nanopillar light emitting diodes (LEDs), ∼150 nm in diameter and 700 nm in height, were fabricated by inductively coupled plasma etching using a Ni self-assembled nano-size mask. 2.5- and 7-fold improvement in the photoluminescence intensity was recorded for the 515 and 543 nm green LED sample, respectively. Since the size and the shape of both samples were similar, it is believed that the higher In content LEDs would produce more strain relaxation through the fabrication of a nanopillar.

► The green MQW nanopillar LEDs were fabricated by ICP etching using a Ni nano-size mask.
► The PL intensity of the 515 and 543 nm sample showed 2.5 and 7 times improvement, respectively.
► Bigger enhancement of a longer wavelength sample was caused by more strain relaxation.
► At the same wavelength, nanopillar showed a superior PL intensity compared with conventional sample.