GIST develops a source technology having a 30% increased green LED luminance efficiency

- Announced in the ‘Advanced Functional Materials’-

 - Opens an opportunity to preoccupy the international LED lights market- 

            

 

                     

 

Gwangju Institute of Science & Technology(GIST, president: Jung Ho SONU) announced that it developed a source technology having a maximum of 30% increased InGaN* green LED luminescence efficiency, a next generation light source, through a research under the supervision by Gwangju Institute of Science & Technology(GIST, president: Jung Ho SONU), professor Gun Young Jung (School of Materials Science and Engineering), and Senior research scientist, Ph. D. Mun Seok Jeong (Advanced Photonics Research Institute).

 

                                     

The research result was selected as a noteworthy thesis and posted as a frontispiece in the April 9, 2010 edition of “Advanced Functional Materials, IF = 6.808”, which is a world renowned science journal in the field of material engineering.

According to this new technology, the luminescence efficiency has been increased by at least 30% by an optical waveguide phenomenon of a zinc oxide nano stick without reducing the electrical characteristics as compared to the existing LED.

First of all, the research team grew a ZnO stick on an ITO electrode layer of a InGaN green LED(luminescence diode) using the hydrothermal method. Next, the team studied features including whether or not the ZnO stick accepts the light generated by the LED and emits the light effectively, using a confocal electroluminescence microscope which the team also developed.

As a result, the team observed that, during an LED luminescence, the light delivered through the ZnO stick is effectively extracted to the end of the stick. This proved that the ZnO stick functions as a tube where light passes through, and that the luminescence efficiency of the LED structure is increased.

 

                              

 

LED is one of the green energies leading the ‘low carbon green growth’. It has high energy efficiency and environmentally friendly characteristics, and is gaining attentions as a next generation light source.

Unlike existing lights such as incandescent light and fluorescent light, LED has high efficiency for converting electrical energy to light energy, saving by a maximum of 90% of energy.

Furthermore, if we replace 30 % of the domestic lights with LED lights by 2015, 16 billion kWh electricity(equivalent to electricity produced by two million kW grade nuclear power plants) will be saved every year, and 6.8 million tons less CO2 will be emitted.

Professor Gun Young Jung said that “in this research, we grew a ZnO stick, which can easily function as an optical waveguide in terms of material costs and processing costs at a low temperature without effecting the LEC electrode structure, thereby innovatively enhancing the luminescence efficiency. If we combine this research results with nano technologies such as “research on vertical array of a ZnO load using lithography method for large area application”, we may enjoy a dominant position in the world LED lights market which is expected to account for 110 billion dollars in 2015”.

This research was supported by the general researcher support project and nano source technology development project which were proceeded by Ministry of Education, Science and Technology(minister: Gyeong Man Ahn) and National Research Foundation of Korea(president: Chan Mo Park).