Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Grain orientation boosts thermoelectric performance

The peak dimensionless thermoelectric figure-of-merit (ZT) of Bi2Te3-based n-type single crystals is about 0.85 in the ab plane at room temperature, which has not been improved over the last 50 years due to the high thermal conductivity of 1.65 W m−1 K−1 even though the power factor is 47  10−4 W m−1 K−2.  Credit Nano Letters
The peak dimensionless thermoelectric figure-of-merit (ZT) of Bi2Te3-based n-type single crystals is about 0.85 in the ab plane at room temperature, which has not been improved over the last 50 years due to the high thermal conductivity of 1.65 W m−1 K−1 even though the power factor is 47 10−4 W m−1 K−2. Credit Nano Letters

Abstract:
Thermoelectric materials promise everything from clean power for cars to clean power from the sun, but making these materials widely useful has been a challenge.

Grain orientation boosts thermoelectric performance

Chestnut Hill, MA | Posted on January 23rd, 2011

Now researchers from Boston College, MIT and GMZ Energy have developed an inexpensive, simple mechanical process for achieving a major increase in the efficiency of a common thermoelectric material: bismuth telluride selenide (BiTeSe), which has been used in commercial devices since the 1950s. "Power generation applications for thermoelectrics are not big now because the materials aren't good enough," said MIT professor Gang Chen. He believes their findings could pave the way for a new generation of products - from semiconductors and air conditioners to car exhaust systems and solar power technology - that run cleaner.

Xiao Yan and his colleagues from BC, MIT and GMZ Energy achieved a 22% improvement in peak thermoelectric figure of merit (ZT - see 1 below) from 0.85 to 1.04 at 125 degrees C in Bi2Te2.7Se0.3 by repressing the as-pressed samples. The main improvement is the large increase of electrical conductivity with only small increase of thermal conductivity and similar Seebeck coefficient. "We want to attain the single-crystal-like high power factor (see 2 below) by preparing preferential grain orientation while maintaining low thermal conductivity by nanocomposite approach," said Boston College professor Zhifeng Ren.

An innovative mechanical process technique was employed by Xiao Yan and his co-workers from BC, MIT and GMZ Energy. As-pressed samples were initially obtained by ball milling the mixture of individual element materials into alloyed BiTeSe nanopowders and then hot pressing the powder into bulk forms with nano constituents. Then as-pressed bulks were pressed again at elevated temperatures in a bigger diameter die to obtain re-pressed bulk samples. "During repressing process, lateral flow takes place, which helps to orient the grains and thus improve the power factor," explained Ren and Chen.

This work was published in Nano Letters, pubs.acs.org/doi/abs/10.1021/nl101156v

(1) ZT is a measure of the thermoelectric performance of a material

(2) Power factor is defined as a product of squared Seebeck coefficient and electrical conductivity.

####

For more information, please click here

Contacts:
Ed Hayward
Boston College Office of Public Affairs
617-552-4826

Copyright © Boston College

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Innovation in Nanotechnology is Focus of Symposium: Annual event brings international experts to Northwestern Oct. 6 September 29th, 2016

Cambrios at CEATEC - Japan 2016 September 29th, 2016

Picosun patents ALD nanolaminate to prevent electronics from overheating September 28th, 2016

Leti and Taiwanese Tech Organizations Sponsoring Workshop in Taipei on MEMS, IoT, Smart Lighting Applications, System Reliability & Security September 28th, 2016

Possible Futures

Crystalline Fault Lines Provide Pathway for Solar Cell Current: New tomographic AFM imaging technique reveals that microstructural defects, generally thought to be detrimental, actually improve conductivity in cadmium telluride solar cells September 26th, 2016

Researchers at the Catalan Institute of Nanoscience and Nanotechnology show that bending semiconductors generates electricity September 26th, 2016

Chains of nanogold forged with atomic precision September 23rd, 2016

Tattoo therapy could ease chronic disease: Rice-made nanoparticles tested at Baylor College of Medicine may help control autoimmune diseases September 23rd, 2016

Materials/Metamaterials

Innovation in Nanotechnology is Focus of Symposium: Annual event brings international experts to Northwestern Oct. 6 September 29th, 2016

Cambrios at CEATEC - Japan 2016 September 29th, 2016

Picosun patents ALD nanolaminate to prevent electronics from overheating September 28th, 2016

UNAM develops successful nano edible coating which increases life food September 27th, 2016

Environment

Coffee-infused foam removes lead from contaminated water September 21st, 2016

Mathematical nanotoxicoproteomics: Quantitative characterization of effects of multi-walled carbon nanotubes: This research article by Dr. Subhash Basak et al. will be published in Current Computer-Aided Drug Design, Volume 12, 2016 September 2nd, 2016

Nanofur for oil spill cleanup: Materials researchers learn from aquatic ferns: Hairy plant leaves are highly oil-absorbing / publication in bioinspiration & biomimetics / video on absorption capacity August 25th, 2016

Researchers watch catalysts at work August 19th, 2016

Energy

Cambrios at CEATEC - Japan 2016 September 29th, 2016

Crystalline Fault Lines Provide Pathway for Solar Cell Current: New tomographic AFM imaging technique reveals that microstructural defects, generally thought to be detrimental, actually improve conductivity in cadmium telluride solar cells September 26th, 2016

Researchers at the Catalan Institute of Nanoscience and Nanotechnology show that bending semiconductors generates electricity September 26th, 2016

Semiconducting inorganic double helix: New flexible semiconductor for electronics, solar technology and photo catalysis September 15th, 2016

Automotive/Transportation

Carbon-coated iron catalyst structure could lead to more-active fuel cells September 15th, 2016

GLOBALFOUNDRIES Launches Embedded MRAM on 22FDX Platform: High-performance embedded non-volatile memory solution is ideally suited for emerging applications in advanced IoT and automotive September 15th, 2016

GLOBALFOUNDRIES Extends FDX Roadmap with 12nm FD-SOI Technology: 12FDXTM delivers full-node scaling, ultra-low power, and software-controlled performance on demand September 8th, 2016

Imperial College use Kleindiek micromanipulators in their research into electrochemical energy devices September 6th, 2016

Solar/Photovoltaic

Cambrios at CEATEC - Japan 2016 September 29th, 2016

Crystalline Fault Lines Provide Pathway for Solar Cell Current: New tomographic AFM imaging technique reveals that microstructural defects, generally thought to be detrimental, actually improve conductivity in cadmium telluride solar cells September 26th, 2016

Semiconducting inorganic double helix: New flexible semiconductor for electronics, solar technology and photo catalysis September 15th, 2016

New perovskite research discoveries may lead to solar cell, LED advances September 12th, 2016

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







Car Brands
Buy website traffic