Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists from the UAB and ICMAB achieve unprecedented control of formation of nanostructures

08.05.2002


Atomic Force Microscope image of nanoislands


A team of researchers from the Universitat Autònoma de Barcelona, together with researchers from ICMAB (CSIC) and other Russian and Ukrainian scientists, have discovered an unprecedented method for accurately controlling the formation of nanometric structures made of semiconducting material in the form of islets, using promising optoelectronic applications in the most advanced communication technology. The discovery was featured as a cover story by the prestigious Nanotechnology magazine.

One of the areas that is currently being most thoroughly researched with respect to future applications is the manipulation of surfaces on a nanometric scale, up to the point of practically constructing and manipulating structures atom by atom, and whereby the quantum effects could give these materials new properties, with revolutionary applications for nanoelectronics, optoelectronics and computing. One of these structures is the so-called quantum dot, in which electrons lose their capacity for mobility in spatial dimensions and become confined to a zero dimension (a dot). At the moment, the experiments with semiconductor materials most similar to quantum dots are the formation of nanoilles, semiconductor islets of several tens of nanometers of diameter and height. These islets can be produced using lithographic techniques, “printing” them onto the surface of a substrate, but for a decade now, scientists have been working on a new, and more efficient and stable, method for constructing them: the spontaneous formation of nanoilles.

Now, a team of researchers from the Universitat Autònoma de Barcelona, together with researchers from the Institute of the Science of Materials in Barcelona (a CSIC institute on the UAB campus), the Institute of Microstructure Physics in Nizhny Novgorod (Russia) and the Institute of Semiconductor Physics in Kiev (Ukraine), have developed unprecedented accuracy in the control of the growth of nanoilles. These researchers have made a detailed study of the spontaneous formation of SiGe nanoilles (semiconductor material) by depositing thin layers of geranium atoms onto silicon substrates, and have observed, for the first time, how they separately affect the thickness of the layers of geranium and the temperature of formation of nanoilles in their distribution, composition and in two possible forms: pyramid or rounded.



The team of researchers has developed an unprecedented level of control of the distribution, shape and composition of the SiGe nanoilles, such that by varying the thickness of the layers of geranium and the temperature of the silicon substrate they can obtain, at will, large densities of small pyramid islets, large round islets distributed at much lower densities or even a uniform mixture of pyramid and rounded islets. As for the control of the composition of the islets’ SiGe semiconductor material, the researchers have observed that as temperature is increased, so does the silicon content, independently of the form and distribution of the nanoilles.

This research was later considered worthy of being the cover story in the prestigious Nanotechnology magazine, and may have important implications for the fields of nanoelectronics and optoelectronics, as semiconductor lasers (such as those used in ‘laser pointers’) manufactured with this material could emit light in a far wider range of colours than at present. It is expected that this discovery will improve the transmission of information via fibre optics and in electronic circuits, the basis of new communication technologies.

The researchers are now working on the formation of other quantum nanostructures, most particularly semiconductor nanolagoons, which are formed spontaneously on depositing layers of cadmium selenium (CdSe) onto zinc selenium (ZnSe) substrates.

Octavi López Coronado | alphagalileo

More articles from Physics and Astronomy:

nachricht Explosion on Jupiter-sized star 10 times more powerful than ever seen on our sun
18.04.2019 | University of Warwick

nachricht In vivo super-resolution photoacoustic computed tomography by localization of single dyed droplets
18.04.2019 | Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Explosion on Jupiter-sized star 10 times more powerful than ever seen on our sun

A stellar flare 10 times more powerful than anything seen on our sun has burst from an ultracool star almost the same size as Jupiter

  • Coolest and smallest star to produce a superflare found
  • Star is a tenth of the radius of our Sun
  • Researchers led by University of Warwick could only see...

Im Focus: Quantum simulation more stable than expected

A localization phenomenon boosts the accuracy of solving quantum many-body problems with quantum computers which are otherwise challenging for conventional computers. This brings such digital quantum simulation within reach on quantum devices available today.

Quantum computers promise to solve certain computational problems exponentially faster than any classical machine. “A particularly promising application is the...

Im Focus: Largest, fastest array of microscopic 'traffic cops' for optical communications

The technology could revolutionize how information travels through data centers and artificial intelligence networks

Engineers at the University of California, Berkeley have built a new photonic switch that can control the direction of light passing through optical fibers...

Im Focus: A long-distance relationship in femtoseconds

Physicists observe how electron-hole pairs drift apart at ultrafast speed, but still remain strongly bound.

Modern electronics relies on ultrafast charge motion on ever shorter length scales. Physicists from Regensburg and Gothenburg have now succeeded in resolving a...

Im Focus: Researchers 3D print metamaterials with novel optical properties

Engineers create novel optical devices, including a moth eye-inspired omnidirectional microwave antenna

A team of engineers at Tufts University has developed a series of 3D printed metamaterials with unique microwave or optical properties that go beyond what is...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

First dust conference in the Central Asian part of the earth’s dust belt

15.04.2019 | Event News

Fraunhofer FHR at the IEEE Radar Conference 2019 in Boston, USA

09.04.2019 | Event News

 
Latest News

New automated biological-sample analysis systems to accelerate disease detection

18.04.2019 | Life Sciences

Explosion on Jupiter-sized star 10 times more powerful than ever seen on our sun

18.04.2019 | Physics and Astronomy

New eDNA technology used to quickly assess coral reefs

18.04.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>