Subscribe to our free daily newsletters
  Solar Energy News  




Subscribe to our free daily newsletters



SOLAR DAILY
Scientists explain unusual and effective features in perovskite
by Staff Writers
Moscow, Russia (SPX) Jul 01, 2016


Praseodymium atoms are shown in green, oxygen atoms in orange, and titanium atoms in purple. Image courtesy MIPT. For a larger version of this image please go here.

Perovskite is a material with an almost ideal structure. The majority of high-temperature superconductors are perovskite-based due to their non-ideal structure. The material can also be used to produce flexible solar batteries without rare-earth metals, which would help to reduce costs and enable large-scale manufacture.

One of the authors notes the manganite-like properties of perovskites. "This material exhibits many interesting and intriguing properties, most notably giant magnetoresistance. Many manganite properties are unknown, despite the fact that manganites have been studied for decades. We tried to work out what the conduction mechanism is of one of the most common compounds - Pr1-xCaxMnO3," he says. All these features have been experimentally discovered, but the processes to explain these unique properties are unknown.

Semiconductors were discovered more than 150 years ago. Electricity was a new development at the time. It was obvious that there were isolators like rubber and glass, conductors like copper and gold, and some uncertain materials, semiconductors, which did not fit into any category. The mechanisms of semiconductors remained unknown for about a century. It was not until the 1930s that the problem was solved and the first transistor was made. Nowadays it is difficult to imagine any electronic device without transistors.

Unfortunately, it is not possible to see charge movement in a material under a microscope. This is why researchers at Terahertz Spectroscopy Laboratory decided to use indirect detection methods. To test which particles are conductive, they applied different frequency voltages and measured the relationship between frequency and induced current. The scientists measured the frequency and temperature dependence of conductivity and permittivity in a broad frequency range (5-3000 cm-1) to cover all the bases.

Wide temperature ranges - from 10 to 300 K (-263 to 27 C) - of the samples were obtained to distinguish similar dependences of samples with different conduction mechanisms. But even this was insufficient to clarify the nature of charge carries. For this reason, researchers compared perovskites with different ratios of calcium (Ca) and praseodymium (Pr).

The group of scientists headed by Boris Gorshunov, Terahertz Spectroscopy Laboratory supervisor, (Lenar Kadyrov PhD, and laboratory scientists Elena Zhukova and Vladimir Anzin are also authors of this article) thus discovered that the charge carriers in Pr1-xCaxMnO3 perovskites are polarons.

A polaron is an electron moving through the constituent atoms of a material, causing the neighboring positive charges to shift toward it and the neighboring negative charges to shift away. The properties of perovskites are ideal for electron-phonon (phonons are vibrations in a crystal lattice) coupling, determined by the interplay between symmetry breaking interactions.

The researchers established that polarons move coherently (as one unit). That is to say charge carriers behave more like uncoupled particles. The idea of coherence is used in lasers, superconductors, highly accurate distance measurements, quantum calculations etc.

Establishing how conduction occurs could help perovskite research projects and large-scale applications to progress. For example, there is already a high-efficiency perovskite-based device for separating water into oxygen and hydrogen. Perovskites can also be used as LEDs, however they are currently only able to function at the temperature of liquid nitrogen.


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only

.


Related Links
Moscow Institute of Physics and Technology
All About Solar Energy at SolarDaily.com






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

Previous Report
SOLAR DAILY
'Flower Power': Photovoltaic cells replicate rose petals
Karlsruher, Germany (SPX) Jun 28, 2016
With a surface resembling that of plants, solar cells improve light-harvesting and thus generate more power. Scientists of KIT (Karlsruhe Institute of Technology) reproduced the epidermal cells of rose petals that have particularly good antireflection properties and integrated the transparent replicas into an organic solar cell. This resulted in a relative efficiency gain of twelve percent. An a ... read more


SOLAR DAILY
Study shows trees with altered lignin are better for biofuels

Solar exposure energizes muddy microbes

Chemists find new way to recycle plastic waste into fuel

Bioenergy integrated in the bio-based economy crucial to meet climate targets

SOLAR DAILY
Grade-school students teach a robot to help themselves learn geometry

'Squishy' motors and wheels give soft robots a new ride

China's Midea buys nearly half of German robotics firm Kuka

Firm unveils 'robot dog' that does the dishes

SOLAR DAILY
More wind power added to French grid

How China can ramp up wind power

Scotland investing more in offshore wind

Gamesa, Siemens join forces to create global wind power leader

SOLAR DAILY
Volkswagen out to fix big diesels in emissions scandal

Tesla fatal crash is setback to autonomous cars

VW still long way from drawing line under engine-rigging scandal

Record VW payout in US 'dieselgate' settlement

SOLAR DAILY
Activists denounce murder of Philippine anti-coal campaigner

Coal dust kills 23,000 per year in EU: report

Next-generation fluorescent and LED lighting thanks to new phosphor

AMA Report Affirms Human Health And Environmental Impacts From LEDS

SOLAR DAILY
EDF nuclear project 'more difficult' after Brexit: Sapin

Expert says most nuclear fuel melted at Fukushima nuclear plant

Mitsubishi joins EDF in bid to save reactor builder Areva

Putin: Russia, China to Step Up Nuclear Energy Cooperation

SOLAR DAILY
Sweden's 100 percent carbon-free emissions challenge

Norway MPs vote to go carbon neutral by 2030

Algorithm could help detect and reduce power grid faults

It pays to increase energy consumption

SOLAR DAILY
NASA Maps California Drought Effects on Sierra Trees

Where do rubber trees get their rubber

Significant humus loss in forests of the Bavarian Alps

Botanical diversity unraveled in a previously understudied forest in Angola




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News






The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement