Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Innovative nanomaterials processing points to advances in semiconductor optoelectronics

15.11.2005


Electron diffraction pattern of PbS nanoparticles in zeolite X


Optical and structural properties of PbS nanoparticles produced in Zeolite Na-X

The study of semiconductor nanoparticles embedded in a matrix is currently a very active research area. These small particles have physicochemical properties quite different from those in the bulk material. A great variety of semiconductors nanoparticles have been synthesized in different matrix such as polymers, glasses and zeolites with the main purpose to modify their properties by controlling the particle size. Alterations to these properties mean they can be tailored to specific applications in the fields of non-linear optics, photovoltaic conversion, catalysis, optoelectronics, etc.

In this work, published in AZojomo*, by M. Flores-Acosta, R. Pérez-Salas, M. Sotelo-Lerma, F. F. Castillón-Barraza and R. Ramírez-Bon from Unidad Querétaro, Universidad de Sonora and Universidad Nacional Autónoma de México, PbS nanoparticles were synthesized in zeolite Na-X by means of ionic exchange processes in alkaline aqueous solutions. They reported the optical and structural properties of the system PbS-Na-X zeolite.



The 4.0nm PbS nanoparticles have spherical shape, the crystalline structure of galena and are embedded uniformly in the zeolite matrix. The 1se-1ph and 1pe-1ph excitonic transitions observed in the absorption spectra of the PbS-Na-X system is explained in terms of the crystalline quality of the PbS nanoparticles.

The results show that spherical PbS nanoparticles are formed not inside the zeolite cages but outside, embedded in the zeolite matrix. The absorption spectra of the samples display exciton absorption bands at much higher energy than the fundamental absorption edge of bulk PbS. This result is a consequence of strong quantum confinement effects produced by the reduced size of the PbS nanoparticles as compared to the exciton Bohr diameter of bulk PbS.

Dr. Ian Birkby | EurekAlert!
Further information:
http://www.azonetwork.com

More articles from Physics and Astronomy:

nachricht Magnetic field traces gas and dust swirling around supermassive black hole
22.02.2018 | Royal Astronomical Society

nachricht UMass Amherst physicists contribute to dark matter detector success
22.02.2018 | University of Massachusetts at Amherst

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: Developing reliable quantum computers

International research team makes important step on the path to solving certification problems

Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Stiffness matters

22.02.2018 | Life Sciences

Magnetic field traces gas and dust swirling around supermassive black hole

22.02.2018 | Physics and Astronomy

First evidence of surprising ocean warming around Galápagos corals

22.02.2018 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>