News Article

Researchers Build 3D GaN-based Networks On Carbon 'foam'

SIngle step hydride vapour phase epitaxy process grows GaN on Aerographite  template

Scientists from universities in Germany, Moldova and Australia have grown a 3D GaN hybrid network on a novel flexible carbon 'foam' called Aerographite, using a single step hydride vapour phase epitaxy process (HVPE). 

The work, which was published in Nature Scientific Reports, opens up the possibility of making flexible, semiconducting composites that could be used as next generation materials for electronic, photonic, and sensors applications.

Aerographite is a synthetic foam made from a mechanically flexible, porous interconnected network of hollow carbon tubes with micron-scale diameters and a wall thickness of around 15nm. Researchers at the University of Kiel and the Technical University of Hamburg in Germany, who were involved in this recent work, developed the foam a couple of years ago.

GaN's direct and wide bandgap (~3.4eV at room temperature), high mechanical stability, and large electrical/thermal conductivity mean that nano- and microstructures based on GaN are promising candidates for next generation nanoelectronic, nanopiezotronic, and photonic devices, LEDs and lasers, chemical and biosensors.

Various techniques have been used for versatile growth of different GaN structures, however almost all are based on one or 2D epitaxially grown architectures, such a nanorods, nanowires, nanotubes etc. and their arrays on particular substrates.

Unusually, in this case, the researchers used a single step HVPE process to grow the GaN nano- and microstructures on the surface of Aerographite tubes. In the HVPE process, homogeneous growth of GaN nano- and microstructures occurs on both the inner and the outer surfaces of the carbon tubes in the entire Aerographite network while several growth directions are indicative of the direct free growth, according to the paper.

(a-c) Growth of the GaN nano- and microcrystals on Aerographite network from partial to complete coverage. (d-f) Uniformity and morphology of the grown GaN nano- and microstructures on the AG tubes. (g) Growth of GaN nano- and microcrystals on inner and outer surfaces. (h-i) Low and corresponding high magnification SEM images demonstrating growth of hexagonally facetted GaN nanocrystals at the inner surface of the tube.

The team found that the grown GaN nano- and microstructures were strongly attached on the surface of the thin graphite walls which prevent their agglomeration. Studies also revealed the highly crystalline nature of these GaN structures. Cathodoluminescence results showed that they exhibited intense near-band-edge UV emission, and yellow emission usually attributed to host defects.

The  scientists say that the 3D network retains the flexible behavior of the Aerographite template, which opens up a wide range of application opportunities. In particular, the stress dependent electrical conductivity of the Aerographite-GaN hybrid 3D network might be useful for designing different kinds of sensors and self-reporting materials, the team suggest.

'Three-dimensional Aerographite-GaN hybrid networks: Single step fabrication of porous and mechanically flexible materials for multifunctional applications' by Arnim Schuchardt et al, Scientific Reports 5, Article number: 8839 doi:10.1038/srep08839

AngelTech Live III: Join us on 12 April 2021!

AngelTech Live III will be broadcast on 12 April 2021, 10am BST, rebroadcast on 14 April (10am CTT) and 16 April (10am PST) and will feature online versions of the market-leading physical events: CS International and PIC International PLUS a brand new Silicon Semiconductor International Track!

Thanks to the great diversity of the semiconductor industry, we are always chasing new markets and developing a range of exciting technologies.

2021 is no different. Over the last few months interest in deep-UV LEDs has rocketed, due to its capability to disinfect and sanitise areas and combat Covid-19. We shall consider a roadmap for this device, along with technologies for boosting its output.

We shall also look at microLEDs, a display with many wonderful attributes, identifying processes for handling the mass transfer of tiny emitters that hold the key to commercialisation of this technology.

We shall also discuss electrification of transportation, underpinned by wide bandgap power electronics and supported by blue lasers that are ideal for processing copper.

Additional areas we will cover include the development of GaN ICs, to improve the reach of power electronics; the great strides that have been made with gallium oxide; and a look at new materials, such as cubic GaN and AlScN.

Having attracted 1500 delegates over the last 2 online summits, the 3rd event promises to be even bigger and better – with 3 interactive sessions over 1 day and will once again prove to be a key event across the semiconductor and photonic integrated circuits calendar.

So make sure you sign up today and discover the latest cutting edge developments across the compound semiconductor and integrated photonics value chain.



Search the news archive

To close this popup you can press escape or click the close icon.
Register - Step 1

You may choose to subscribe to the Compound Semiconductor Magazine, the Compound Semiconductor Newsletter, or both. You may also request additional information if required, before submitting your application.

Please subscribe me to:


You chose the industry type of "Other"

Please enter the industry that you work in:
Please enter the industry that you work in:
Live Event