Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Structural and Optical Properties of Disc-in-Wire InGaN/GaN LEDs



Scott A. Wight, Babak Nikoobakht


This study aims to examine the role of the microstructure and optical properties of InGaN/GaN nanowire LED structures on Si (111) having different nanowire densities. Cathodoluminescence measurements show that all samples exhibit broad emission around the intended 635nm wavelength. The emission intensity of each sample varies due to a competition between the formation of coalescence defects, which tends to decrease the overall emission intensity, and the absolute number of emitting nanowires, which tends to increase the overall emission intensity. The width of the emission peak is likely due to variations in the morphology of the InGaN within the wires, as faceted layers with different thicknesses and quantum dots are observed by Transmission Electron Microscopy. Non-epitaxial 6-fold symmetric lateral branching, called "nanocrowns," emanate from stacking faults within the active regions. These features quench optical emission as a result of multiple grain boundaries between the nanocrown and nanowire.
Nano Letters


InGaN, Disc-in-wire nanowire, Cathodoluminescence, LEDs


Wight, S. and Nikoobakht, B. (2015), Structural and Optical Properties of Disc-in-Wire InGaN/GaN LEDs, Nano Letters, [online], (Accessed May 17, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created February 6, 2015, Updated March 10, 2023