Local nanotip arrays sculptured by atomic force microscopy to enhance the light-output efficiency of GaN-based light-emitting diode structures.
In this work, local nanotip arrays on GaN-based light-emitting (LED) structures were fabricated through nano-oxidation using an atomic force microscope (AFM). The photoluminescence (PL) intensity of the InGaN/GaN multiple quantum wells (MQWs) active layer and the light extraction efficiency of the LED structure were enhanced by forming this nanotips structure to serve as a graded-refractive index layer, which is further validated by the finite-difference time-domain analysis. The PL emission peak of the MQWs active layer has a blue-shift phenomenon that is caused by a partial reduction of the strain on the InGaN well. It is expected that our approach opens a promising route for simultaneously enhancing both the internal quantum efficiency and the light extraction efficiency of GaN-based LEDs. The proposed AFM-based method will be of importance for local patterning the light emitting components for optoelectronic applications.
Institute of Electronics Engineering, National Taiwan University, 1, Sec. 4, Roosevelt Road, Taipei 106, Taiwan.
Chun-Ying
CY
Huang
Yung-Chi
YC
Yao
Ya-Ju
YJ
Lee
Tai-Yuan
TY
Lin
Wen-Jang
WJ
Kao
Jih
J
Shang Hwang
Ying-Jay
YJ
Yang
Ji-Lin
JL
Shen