Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Ben-Gurion University of the Negev develops thin films showing promise for solar applications

10.09.2009
Researchers at Ben-Gurion University of the Negev have developed thin films that exhibit carrier multiplication (CM). This development is of great interest for future solar cells.

The films were synthesized at BGU by Prof. Yuval Golan and PhD student Anna Osherov of the Department of Materials Engineering and the Ilse Katz Institute for Nanoscale Science and Technology. The letter was published this week in Nature Physics.

One of the important factors limiting solar-cell efficiency is that incident photons generate only one electron–hole pair, irrespective of the photon energy. Any excess photon energy is lost as heat.

Carrier Multiplication (CM) has been thought to be enhanced significantly in nanocrystalline materials such as quantum dots, owing to their discrete energy levels and enhanced Coulomb interactions.

The BGU team demonstrated that contrary to this expectation, for a given photon energy, carrier multiplication occurs more efficiently in bulk PbS and PbSe films than in nanocrystalline films of the same materials.

"Films developed at BGU show CM, in which each incoming photon (tiny quantity of sunlight) creates more than one electron-hole pair," Golan explains. "This can potentially be used for making more efficient solar cells. The new physics behind this work are that while CM has been mostly demonstrated in nanocrystalline materials ("quantum dots"), we now show that CM can be obtained also in single crystal ('bulk') films of lead sulfide and lead selenide."

Notably, the films were prepared using chemical solution deposition, an attractive, inexpensive deposition technique for which the Golan group at BGU has received considerable recognition. The research was carried out as part of an international collaboration with counterparts in France and the Netherlands.

J.J.H. Pijpers, R. Ulbricht, K.J. Tielrooij, A. Osherov, Y. Golan, C. Delerue, G. Allan and M. Bonn, "Assessment of Carrier Multiplication efficiency in bulk PbSe and PbS", Nature Physics (2009) in press.

About Ben-Gurion University of the Negev and American Associates

Ben-Gurion University of the Negev is a world-renowned institute of research and higher learning with some 19,000 students on campuses in Beer-Sheva, Sede Boqer and Eilat in Israel's southern desert. It is a university with a conscience, where the highest academic standards are integrated with community involvement, committed to sustainable development of the Negev. Founded in 1972, American Associates, Ben-Gurion University of the Negev plays a vital role in helping the University fulfill its unique responsibility to develop the Negev, reach out to its local community and its Arab neighbors, and share its expertise with the world.

Andrew Lavin | EurekAlert!
Further information:
http://www.alavin.com
http://www.aabgu.org

More articles from Physics and Astronomy:

nachricht Applicability of dynamic facilitation theory to binary hard disk systems
08.12.2016 | Nagoya Institute of Technology

nachricht Will Earth still exist 5 billion years from now?
08.12.2016 | KU Leuven

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: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Closing the carbon loop

08.12.2016 | Life Sciences

Applicability of dynamic facilitation theory to binary hard disk systems

08.12.2016 | Physics and Astronomy

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D

08.12.2016 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>