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Metz, France | Posted: October 14, 2019
Summary Sentence:
A UMI team led by Prof. Abdallah Ougazzaden has created a new technology for pick-and-place III-nitride nanostructure LEDs
Full Summary:
The UMI researchers have grown self-organized GaN nanorod LED devices that were mechanically transfered to another substrate. Hexagonal h-BN provided a key role in decoupling substrate from nanodevice and permitting lift-off. This new technology is demonstrated at the wafer scale and can result in commericalization of nano-LEDs and other nanoscale nitride optoelectronic devices.
BN enables nano-LED lift-offHexagonal boron nitride (h-BN) is a promising 2D template that decouples substrate effects from the layer above it by van der Waals epitaxy, because there are only weak forces out of the plane of the h-BN. van der Waals epitaxy also permits convenient mechanical transfer of devices grown on their surface to an appropriate substrate. Here, van der Waals epitaxial growth resulting in the formation of self-organized GaN nanorods on h-BN templates is demonstrated. This approach to the growth of III-N nanostructures avoids transfer processes and scaling issues seen with other 2D materials, since both the 1D (GaN nanorods) and 2D (h-BN) are grown at the wafer-scale and in one growth run. Further, this process is used to grow vertical core–shell p-GaN/InGaN/n-GaN nano-PIN device structures on wafer-scale 2D h-BN on sapphire and silicon substrates. The high quality of the core–shell nanostructures is confirmed by detailed electron microscopy study, which gives more insight into the nanorod formation mechanism on 2D material. Mechanical transfer of nanostructures on sapphire substrates to copper tape is then demon- strated, with no resulting damage of nanorods. Use of MOVPE grown large-area h-BN to realize nanostructures is a significant advancement and can lead to new nanodevice architectures needed for next-generation optoelectronic devices.
