MISIS, Lebedev Physics Institute of the Russian Academy of Sciences, University of Goryeo: Method of elimination of defects of micro- and nanovetodiodes

Main article: LED (LED lighting)

2024: Introduction of LED defect elimination method for LED screens and VR glasses

An international team of scientists from Russia and Korea has improved the method of manufacturing micro- and nano- light diodes for LED screens and VR glasses, which increases their efficiency of converting electricity into light radiation from 5.5% to 10.6%. This technology successfully eliminates defects that cause current leakage. MISIS announced this on July 18, 2024.

source = MISIS

Structure-based LEDs made of gallium nitride and indium-gallium nitride are semiconductor devices that can emit light from blue-violet to green and red color ranges. They are used in lighting, data storage and communication systems. Due to the high brightness, nano- and microvetodiodes are in demand for microdisplay and microproctors in the rapidly developing augmented reality technology market. To create micro- and nanoscale LEDs, the method of dry etching of large LEDs is most often used, that is, removing their side layer with chemicals and plasma.

In the process of creating LEDs less than 30 micrometers, problems often arise. After the dry etching step, defects appear on the diode walls. This leads to an increase in non-radiative recombination, that is, electric energy is converted not into light, but, for example, into heat, "said Luisa Aleksanyan, engineer of the scientific project of the Ultrashirokoson Semiconductors laboratory at NITU MISIS.

One important parameter for evaluating LED performance is internal quantum efficiency, which shows how well the device converts electricity into light. Due to the appearance of defects in structures without additional processing, it is only 5.5%. To solve this problem, various methods are used: high-temperature annealing, coating the surface with various substances and etching the side walls with potassium hydroxide. However, these methods increase the efficiency to only 6.8%.

Scientists of NUST MISIS, Physical Institute named after P.N. Lebedev RAS together with colleagues from Goryeo University have developed a method for eliminating defects.

We added silver nanoparticles coated with silica to the polymer filling the space between the nanovetodiodes. These particles create an alternative energy transmission route for charge carriers, which could improve its ability to emit light. The development led to the maximum improvement of internal quantum efficiency up to 10.6%, - said Candidate of Technical Sciences Alexander Polyakov, head of the laboratory "Ultrashirokosonic Semiconductors" NUST MISIS.