Researchers from Illinois University in Urbana Champaign developed a new way to create more vivid and efficient green LEDs (LED). Using standard industrial combustion technology of semiconductors, they obtained cubic crystals from Gallium nitride (GAN) grown on a silicon substrate. Such crystals are capable of producing powerful green light for solid-state (LED) lighting.
As a rule, GAN crystal is formed in one Of the two crystalline forms: hexagonal or cubic. Hexagonal GAN crystals are thermodynamically stable and more often used as semiconductors. However, in contrast to cubic, they are prone to so-called polarization, when the inner electric field shares negatively charged electrons and positively charged cavities, preventing them by reducing the light output.
so far the only way to produce cubic crystals GaN It was the use of molecular radial epitaxy - a very expensive and slow method of growing crystals. Scientists have developed a cheapest method by creating cubic GANs using lithography and isotropic engraving to form a U-shaped groove on a silicon surface. This non-conductive layer served as a border that gives hexagonal material cubic shape.
Efficient green LEDs will open up new features for solid-state lighting systems. For example, these LEDs will ensure energy savings due to the generation of white light by mixing multiple colors.
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