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Seven reasons why group-III-nitride semiconductors have emerged as the materials of choice for optoelectronic as well as for high-temperature and high-power electronic devices


By
Nasir Alfaraj

August 30, 2016 - Posted in Discussion
Here are seven reasons why group-III-nitride semiconductors have emerged as the materials of choice for optoelectronic as well as for high-temperature and high-power electronic devices:

1. Various electronic devices and components, including high color-fidelity and homogeneous displays, color laser printers, high-density storage media, and underwater communication equipment, require short-wavelength light-emitting capabilities, which can be realized through the integration of group-III-nitride materials into such devices.

2. While zinc selenide (ZnSe)-based semiconductor materials have bandgap values suitable for short-wavelength semiconductor optoelectronic devices, the bond strength in the group II-VI wide-bandgap semiconductors is rather low. The values of the bond energy are 2.3 eV/bond in gallium nitride (GaN) compared to 1.2 eV/bond in ZnSe.

3. Since their bandgaps are not adequately large, silicon and traditional group III-V semiconductors are not suitable for fabricating semiconductor devices operating in the near-UV region of the spectrum. Also, GaAs-based devices cannot be used at high temperatures. The bandgaps of group-III-nitride materials are direct and large. The bandgaps values are 1.9 eV for indium nitride (InN), 3.4 eV for GaN, and 6.2 eV for aluminum nitride (AlN), compared to 1.12 eV for silicon, which has an indirect bandgap, resulting in a less efficient light absorption.

4. Alloying GaN with InN and/or AlN allows for material bandgap tuning in a controllable manner, covering a wide spectral range from deep-ultraviolet to near-infrared.

5. Modern electronic devices require the use of heterostructure technology to fabricate quantum wells and superlattices, which are periodic structures of layered materials with thicknesses of a few nanometers. Using GaN or aluminum gallium nitride (AlGaN) layers as metal diffusion barrier and cladding layers, and GaN or indium gallium nitride (InGaN) as active layers, quantum wells and superlattices can be fabricated.

6. Incorporation of small indium contents in active GaN layers induces a substantial increase in the luminescence efficiency. Therefore, InGaN quantum wells are essential for light-emitting devices.

7. While silicon has a breakdown voltage of 2×105 V/cm, GaN has a considerably higher breakdown voltage of 3×106 V/cm. High breakdown voltage levels are necessary for realizing high-power electronic devices.


References:

Jain, S. C., et al. "III–nitrides: Growth, characterization, and properties." Journal of Applied Physics 87.3 (2000): 965-1006.

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3 Comments
Anonymous
September 21, 2016 at 6:24 PM
This material is most fascinating and changing our World in a big way. This should not be restricted to only 7 reasons, keep on adding reasons to the list!
Anonymous
October 5, 2016 at 1:20 AM
Thanks for the excellent summary. I'd like to note that beside having high breakdown fields, GaN-based power transistors can potentially have on-resistances that are 10 to 20 times lower than silicon-based power devices.
Anonymous
October 11, 2016 at 12:02 AM
With a very high Johnson's figure of merit, GaN is the most suitable semiconductor material for high frequency and power transistors. It's a really exciting area of research and I'm glad that I came across your article!