Formation of nanowires based on rare-earth-doped semiconductors for device applications

Abstract

This paper reviews our recent research about the formation and optical characteristics of GaN:Eu/GaN nanowires (NWs) by organometallic vapor phase epitaxy for application in GaN-based red LEDs. Two types of GaN:Eu/GaN NWs with different configurations are introduced, core–shell and axial geometries. The configuration of GaN:Eu layers on GaN core NWs can be controlled by changing the growth conditions, and affects the properties of Eu luminescence in the GaN NWs. Next, the fabrication process of the NW LEDs towards future possible realization of flexible devices is established, including an etch-back process of the PDMS membranes to expose the top p-GaN contact layers. Finally, a prototype of p-GaN/GaN:Eu/n-GaN NW LEDs on sapphire substrates is fabricated to determine the device characteristics. Sharp red luminescence at room temperature from Eu³⁺ ions is observed under current injection.