Emission peculiarities of high-quantum yield silicon nanoparticles

Mar 13, 2014
Emission peculiarities of high-quantum yield silicon nanoparticles
Figure 1. Photographs (top) and emission spectra (bottom) of silicon quantum dots suspended in methanol. Emission spectra gradually shift from near-infrared to red with decreasing particle size, which is achieved simply by annealing the as-prepared material at different temperatures. Credit: American Chemical Society.

In 1990, scientists reported that nanostructured silicon can emit visible light. This report opened a new frontier for photoelectronics in information technology, called "silicon photonics". Furthermore, the continuous tuning of electromagnetic emission from near-UV to near-infrared wavelengths has been achieved by controlling silicon nanostructures.

The (QY) of this radiation may exceed 70%, and the use of silicon as the emitting material is advantageous because of its abundance and low toxicity to the human body and environment.

These advantages have been expected to stimulate the use of luminescent silicon in various fields; however, commercial applications are still lacking.

In this paper, Ghosh and Shirahata focus on high-QY silicon nanoparticles. It summarizes the peculiarities of their emission, which depends on the preparation method and surface chemistry.

In particular, there are two spectral ranges separated by green light, which can not be smoothly covered using a single synthesis approach. This green boundary is discussed to provide a better understanding of the emission mechanisms.

Those mechanisms are summarized to ascertain the future challenges in the industrial use of silicon-based light emitters. The authors believe that silicon nanophotonics is still in its infancy.

They predict that with high-quality materials of narrow size distribution and controlled surface chemistry in hand, novel photonic structures will be realized in the near future, including biomedical imaging devices, optical amplifiers, sensors, high-efficiency LEDs, and possibly a silicon-based laser.

Explore further: Magneto-optical nonreciprocal devices in silicon photonics

More information: Batu Ghosh and Naoto Shirahata: "Colloidal silicon quantum dots: synthesis and luminescence tuning from the near-UV to the near-IR range." Sci. Technol. Adv. Mater. Vol. 15 (2014) p. 014207. dx.doi.org/10.1088/1468-6996/15/1/014207 . Article published on 17 January 2014

add to favorites email to friend print save as pdf

Related Stories

Making silicon devices responsive to infrared light

Jan 06, 2014

Researchers have tried a variety of methods to develop detectors that are responsive to a broad range of infrared light—which could form imaging arrays for security systems, or solar cells that harness ...

Photonics: Enabling next-generation wireless networks

Mar 12, 2014

Wireless transmission at microwave frequencies is important for high-data-rate transmission applications, such as mobile phone networks, satellite links and remote imaging. Now, Xianshu Luo and colleagues ...

Light from silicon nanocrystal LEDs

Feb 18, 2013

(Phys.org)—Silicon nanocrystals have a size of a few nanometers and possess a high luminous potential. Scientists of KIT and the University of Toronto/Canada have now succeeded in manufacturing silicon-based ...

Recommended for you

PPPL studies plasma's role in synthesizing nanoparticles

5 hours ago

DOE's Princeton Plasma Physics Laboratory (PPPL) has received some $4.3 million of DOE Office of Science funding, over three years, to develop an increased understanding of the role of plasma in the synthesis ...

First ab initio method for characterizing hot carriers

Jul 17, 2014

One of the major road blocks to the design and development of new, more efficient solar cells may have been cleared. Researchers with the Lawrence Berkeley National Laboratory (Berkeley Lab) have developed ...

User comments : 0