Featured Research

from universities, journals, and other organizations

Nanosheets and nanowires

Date:
April 1, 2014
Source:
International Union of Crystallography
Summary:
Researchers have found a convenient way to selectively prepare germanium sulfide nanostructures, including nanosheets and nanowires, that are more active than their bulk counterparts. Germanium monosulfide, GeS, is emerging as one of the most important "IV-VI" semiconductor materials with potential in opto-electronics applications for telecommunications and computing, and as an absorber of light for use in solar energy conversion. One important property is its much lower toxicity and environmental impact when compared to other semiconductors made with cadmium, lead and mercury.

This is a typical TEM image of as-prepared GeS nanowires with the inset showing a selected area electron diffraction pattern taken from GeS nanowires.
Credit: Liang Shi and Yumei Dai

Researchers in China have found a convenient way to selectively prepare germanium sulfide nanostructures, including nanosheets and nanowires, that are more active than their bulk counterparts and could open the way to lower cost and safer optoelectronics, solar energy conversion and faster computer circuitry.

Germanium monosulfide, GeS, is emerging as one of the most important "IV-VI" semiconductor materials with potential in opto-electronics applications for telecommunications and computing, and as an absorber of light for use in solar energy conversion. One important property is its much lower toxicity and environmental impact when compared to other semiconductors made with cadmium, lead and mercury. It is less costly than other materials made with rare and noble metal elements. Indeed, glassy GeS has been used in lasers, fibre optic devices and infrared lenses as well as rewritable optical discs and non-volatile memory devices for several years. It is also used extensively as a solid electrolyte in conductive bridging random access memory (RAM) devices.

The repertoire of this material might be extended much further with the extra control that its use as nanostructured systems might allow. Liang Shi and Yumei Dai of the University of Science and Technology of China, in Hefei, point out that research in this area has lagged behind that with other IV-VI semiconductors. They hope to change that and have focused on how nanosheets and nanowires of GeS might be readily formed. They have used X-ray powder diffraction, transmission electron microscopy, energy-dispersive X-ray spectrometry and scanning electron microscopy to investigate the structure, morphology, composition and optical absorption properties of their samples.

The team used simple "wet" chemistry to synthesis their products using germanium dichloride-dioxane complex, thiourea and oleylamine (OLA) as starting materials. The ingredients were mixed in a sealed reaction flask, blasted with ultrasound to exclude air and then stirred and heated. The team was able to make nanosheets of GeS this way if the process was carried out for several hours at 593 Kelvin. At higher temperature, 613 Kelvin, they found that the sheets wind up into nanowires. Indeed, the precise heating time and temperature allowed them to control the structure of the final product. The team suggests that the rolling up of the nanosheets into nanowires is driven by the surface tension between the sheet and the OLA molecules during the heating.

Having proven the structural integrity of their GeS nanowires and nanosheets, the team built several test devices -- a photoresponsive unit -- which they used to evaluate the optical and electronic properties of the products. The team says that they have demonstrated "outstanding photoresponsive behaviour." This "indicates the potential use of as-synthesized GeS nanosheets and nanowires in solar energy conversion systems, such as the fabrication of photovoltaic devices."


Story Source:

The above story is based on materials provided by International Union of Crystallography. Note: Materials may be edited for content and length.


Journal Reference:

  1. Liang Shi, Yumei Dai. Synthesis, formation mechanism and photoelectric properties of GeS nanosheets and nanowires. Journal of Applied Crystallography, 2014; 47 (2): 527 DOI: 10.1107/S1600576713034535

Cite This Page:

International Union of Crystallography. "Nanosheets and nanowires." ScienceDaily. ScienceDaily, 1 April 2014. <www.sciencedaily.com/releases/2014/04/140401102912.htm>.
International Union of Crystallography. (2014, April 1). Nanosheets and nanowires. ScienceDaily. Retrieved September 16, 2014 from www.sciencedaily.com/releases/2014/04/140401102912.htm
International Union of Crystallography. "Nanosheets and nanowires." ScienceDaily. www.sciencedaily.com/releases/2014/04/140401102912.htm (accessed September 16, 2014).

Share This



More Matter & Energy News

Tuesday, September 16, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Manufacturer Prints 3-D Car In Record Time

Manufacturer Prints 3-D Car In Record Time

Newsy (Sep. 15, 2014) — Automobile manufacturer Local Motors created a drivable electric car using a 3-D printer. Printing the body only took 44 hours. Video provided by Newsy
Powered by NewsLook.com
Refurbished New York Subway Tunnel Unveiled After Sandy Damage

Refurbished New York Subway Tunnel Unveiled After Sandy Damage

Reuters - US Online Video (Sep. 15, 2014) — New York officials unveil subway tunnels that were refurbished after Superstorm Sandy. Nathan Frandino reports. Video provided by Reuters
Powered by NewsLook.com
Frustration As Drone Industry Outpaces Regulation In U.S.

Frustration As Drone Industry Outpaces Regulation In U.S.

Newsy (Sep. 14, 2014) — U.S. firms worry they’re falling behind in the marketplace as the FAA considers how to regulate commercial drones. Video provided by Newsy
Powered by NewsLook.com
Smart Gun Innovators Fear Backlash From Gun Rights Advocates

Smart Gun Innovators Fear Backlash From Gun Rights Advocates

Newsy (Sep. 14, 2014) — Winners of a contest for smart gun design are asking not to be named after others in the industry received threats for marketing similar products. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins