German scientists successfully developed silicon-based LEDs that are colorful and efficient

　　Recently, researchers from Karlsruhe Institute of Technology (KIT) in Germany and the University of Toronto in Canada have successfully used silicon nanocrystals to create efficient silicon-based light-emitting diodes (Si LEDs ) that do not contain heavy metals but can emit light in a variety of colors.

　　Silicon (Si), despite its dominance in microelectronics and photovoltaics, has long been considered unsuitable for the manufacture of light-emitting diodes. However, this is not true at the nanoscale, where tiny silicon nanocrystals made of hundreds or thousands of atoms are able to generate light and have great potential as efficient light emitters. Until now, the manufacture of silicon-based LEDs has been limited to the red visible spectral range and near infrared, so the creation of diodes that can emit colored light is absolutely novel.

　　KIT scientists have discovered that by using monodisperse nanoparticles of different sizes, the color of the light emitted by the diode can be changed. It can be tuned from the deep red spectral region to the orange-yellow spectral region, and the external quantum efficiency can reach 1.1%. It is worth mentioning that the silicon-based light-emitting diodes produced have a surprising long-term stability, which has never been achieved before. The increase in the operating component life is due to the use of only nanoparticles of the same size, which can effectively enhance the stability of sensitive thin-film components, while oversized particles that can cause short circuits are excluded.

　　In addition, the new light-emitting diode is also eye-catching in the homogeneity of its light-emitting area. Researchers said that as liquid-processed silicon-based light-emitting diodes can be manufactured in large quantities at low cost, nanoparticle "groups" will also enter new fields, the relevant potential will be difficult to estimate, and the description of semiconductor components in textbooks may also be rewritten.