Scientists made of colored high efficiency silicon based light-emitting diodes

According to physicist organizational network reported on February 18th, the size of silicon nanocrystals is only a few nanometers, but has a high luminous potential. Now, from the Karlsruhe Institute of Technology (KIT) and the University of Toronto researchers with silicon nanocrystals, made the high silicon based light emitting diode (SiLEDs), which does not contain heavy metals, but can emit different colors of light. Related research reports published in the recently published "nano letters" magazine.

Although silicon is the dominant position in microelectronics and photovoltaic industry, it has long been considered unsuitable for the manufacture of light-emitting diodes. However, this is not correct in the nanometer scale, micro silicon nano crystals composed of hundreds of thousands of atoms can produce light, has become a great potential for high efficient transmitter. So far, the fabrication of silicon-based light-emitting diodes has been limited to the red visible spectrum range and near infrared.

KIT scientists found that by using monodisperse nanoparticles of different sizes, can change the color of the light emitted by the diode. It can be tuned from the deep red spectral region to the orange spectral region with an external quantum efficiency of 1.1%. It is worth mentioning that, made of silicon based light-emitting diodes with surprising long-term stability, which has never been achieved before. The growth of the operating component is due to the use of only the same size of the nanoparticles, which can effectively enhance the stability of sensitive film components, which can lead to excessive size of the short circuit particles are excluded.

This color silicon based light-emitting diode also has the advantage of not containing any heavy metals. Different from other research groups using CdSe, CDs or PBS, the research team used silicon nanoparticles with no toxicity, and silicon reserves on earth is rich, low cost, more conducive to the further development of silicon based light emitting diodes.

In addition, the eye-catching aspect of the new light-emitting diode is also the homogeneity of its light-emitting region. The researchers said that with silicon-based light-emitting diodes or liquid processing can be made with low cost and mass, the nanoparticles "group" will enter a new field, it is difficult to estimate the related potential, and the textbook related semiconductor element description may also be rewritten.