New gallium nitride film method beats the heat

Feb 21, 2006

A team of Los Alamos National Laboratory scientists have developed a method for growing crystalline gallium nitride films at lower temperatures than industry standards. By eliminating the higher temperatures and harsh, reactive environments that currently limit the types of materials used as substrates, the discovery could greatly increase the use of crystalline gallium nitride films in optical-electronic devices, like blue LEDs and laser diodes, high-density optical data storage devices, flat panel displays and solid state lighting.

In research published recently in Applied Physics Letters, the team describes their use of energetic neutral atom-beam lithography/epitaxy to grow crystalline and polycrystalline gallium nitride (GaN) films on bare c-axis-oriented sapphire at temperatures between 100 and 500 degrees Celsius using low kinetic energy nitrogen atoms and a simultaneous flux of gallium metal.

Energetic neutral atom-beam lithography, or ENABLE, is a Los Alamos system that produces a beam of neutral atoms with low kinetic energies that can be used for various kinds of specialized surface chemistry at near room temperatures, often producing results that are unattainable using other techniques. Epitaxy is the process of growing one crystal layer of a material of another crystalline substance.

According to Mark Hoffbauer, the principal investigator for the GaN ENABLE project, "the beauty of using ENABLE for growing crystalline gallium nitride films is that normally the process requires substrate temperatures of 900 to 1,100 degrees Celsius and extremely harsh, reactive environments. Those conditions eliminate a lot of useful materials as substrates because they would melt or be degraded at the higher temperatures. Our lower temperature technique has the potential to allow gallium nitride films to be grown on many more types of inexpensive substrate materials, including glass and certain polymers."

Another researcher on the team, Alex Mueller adds, "The low temperatures employed by ENABLE allow for the incorporation of electronic and magnetic dopants into the films while simultaneously avoiding phase segregation and clustering problems that are limiting the widespread use of these materials in other applications. The fact that there are no impurities inherent in the ENABLE process make defect and impurity free films possible, thereby simplifying device fabrication."

Source: Los Alamos National Laboratory

Explore further: Better thermal-imaging lens from waste sulfur

add to favorites email to friend print save as pdf

Related Stories

Unlocking secrets of new solar material

17 hours ago

(Phys.org) —A new solar material that has the same crystal structure as a mineral first found in the Ural Mountains in 1839 is shooting up the efficiency charts faster than almost anything researchers have ...

NREL test helps make moisture barriers better

Nov 26, 2013

Moisture—in the form of humidity, water spills, or rainfall—spells early demise for cell phones, light-emitting diode (LED) displays, TVs, and solar photovoltaic (PV) panels worldwide.

Understanding what makes a thin film solar cell efficient

Nov 05, 2013

Swiss scientists have developed a new technique for manufacturing high-efficiency, flexible, thin film solar cells from CIGS (copper indium gallium di-selenide) semiconductors. This has enabled them to achieve ...

Two in one solution for low cost polymer LEDs and solar cells

Jul 22, 2013

UNIST researchers report considerable improvement in device performance of polymer-based optoelectronic devices. Published in Nature Photonics today, the new plasmonic material, can be applied to both polymer light-emitting diodes ...

Recommended for you

Better thermal-imaging lens from waste sulfur

10 hours ago

Sulfur left over from refining fossil fuels can be transformed into cheap, lightweight, plastic lenses for infrared devices, including night-vision goggles, a University of Arizona-led international team ...

Robotics goes micro-scale

22 hours ago

(Phys.org) —The development of light-driven 'micro-robots' that can autonomously investigate and manipulate the nano-scale environment in a microscope comes a step closer, thanks to new research from the ...

User comments : 0

More news stories

Better thermal-imaging lens from waste sulfur

Sulfur left over from refining fossil fuels can be transformed into cheap, lightweight, plastic lenses for infrared devices, including night-vision goggles, a University of Arizona-led international team ...

Robotics goes micro-scale

(Phys.org) —The development of light-driven 'micro-robots' that can autonomously investigate and manipulate the nano-scale environment in a microscope comes a step closer, thanks to new research from the ...

Scientists tether lionfish to Cayman reefs

Research done by U.S. scientists in the Cayman Islands suggests that native predators can be trained to gobble up invasive lionfish that colonize regional reefs and voraciously prey on juvenile marine creatures.

White House updating online privacy policy

A new Obama administration privacy policy out Friday explains how the government will gather the user data of online visitors to WhiteHouse.gov, mobile apps and social media sites. It also clarifies that ...