Free Republic
Browse · Search
News/Activism
Topics · Post Article

Skip to comments.

Thin layer of germanium may replace silicon in semiconductors
Phys.Org ^ | April 10, 2013 | Pam Frost Gorder

Posted on 04/10/2013 10:27:07 AM PDT by Red Badger

The same material that formed the first primitive transistors more than 60 years ago can be modified in a new way to advance future electronics, according to a new study.

Chemists at The Ohio State University have developed the technology for making a one-atom-thick sheet of germanium, and found that it conducts electrons more than ten times faster than silicon and five times faster than conventional germanium. The material's structure is closely related to that of graphene—a much-touted two-dimensional material comprised of single layers of carbon atoms. As such, graphene shows unique properties compared to its more common multilayered counterpart, graphite. Graphene has yet to be used commercially, but experts have suggested that it could one day form faster computer chips, and maybe even function as a superconductor, so many labs are working to develop it.

Joshua Goldberger, assistant professor of chemistry at Ohio State, decided to take a different direction and focus on more traditional materials. "Most people think of graphene as the electronic material of the future," Goldberger said. "But silicon and germanium are still the materials of the present. Sixty years' worth of brainpower has gone into developing techniques to make chips out of them. So we've been searching for unique forms of silicon and germanium with advantageous properties, to get the benefits of a new material but with less cost and using existing technology." In a paper published online in the journal ACS Nano, he and his colleagues describe how they were able to create a stable, single layer of germanium atoms. In this form, the crystalline material is called germanane. Researchers have tried to create germanane before. This is the first time anyone has succeeded at growing sufficient quantities of it to measure the material's properties in detail, and demonstrate that it is stable when exposed to air and water.

In nature, germanium tends to form multilayered crystals in which each atomic layer is bonded together; the single-atom layer is normally unstable. To get around this problem, Goldberger's team created multi-layered germanium crystals with calcium atoms wedged between the layers. Then they dissolved away the calcium with water, and plugged the empty chemical bonds that were left behind with hydrogen. The result: they were able to peel off individual layers of germanane. Studded with hydrogen atoms, germanane is even more chemically stable than traditional silicon. It won't oxidize in air and water, as silicon does.

That makes germanane easy to work with using conventional chip manufacturing techniques. The primary thing that makes germanane desirable for optoelectronics is that it has what scientists call a "direct band gap," meaning that light is easily absorbed or emitted. Materials such as conventional silicon and germanium have indirect band gaps, meaning that it is much more difficult for the material to absorb or emit light. "When you try to use a material with an indirect band gap on a solar cell, you have to make it pretty thick if you want enough energy to pass through it to be useful. A material with a direct band gap can do the same job with a piece of material 100 times thinner," Goldberger said.

The first-ever transistors were crafted from germanium in the late 1940s, and they were about the size of a thumbnail. Though transistors have grown microscopic since then—with millions of them packed into every computer chip—germanium still holds potential to advance electronics, the study showed. According to the researchers' calculations, electrons can move through germanane ten times faster through silicon, and five times faster than through conventional germanium. The speed measurement is called electron mobility. With its high mobility, germanane could thus carry the increased load in future high-powered computer chips.

"Mobility is important, because faster computer chips can only be made with faster mobility materials," Golberger said. "When you shrink transistors down to small scales, you need to use higher mobility materials or the transistors will just not work," Goldberger explained. Next, the team is going to explore how to tune the properties of germanane by changing the configuration of the atoms in the single layer.


TOPICS: Business/Economy; Culture/Society; Technical; US: Ohio
KEYWORDS: computers; electronics; ic; technology

The element germanium in its natural state. Researchers at The Ohio State University have developed a technique for making one-atom-thick sheets of germanium for eventual use in electronics. Credit: Joshua Goldberger, The Ohio State University

1 posted on 04/10/2013 10:27:07 AM PDT by Red Badger
[ Post Reply | Private Reply | View Replies]

To: ShadowAce

Ping!........


2 posted on 04/10/2013 10:28:09 AM PDT by Red Badger (Want to be surprised? Google your own name......Want to have fun? Google your friend's names........)
[ Post Reply | Private Reply | To 1 | View Replies]

To: Red Badger

My eyes are going bad...thought this was geraniums and the weekly gardening thread for a minute....


3 posted on 04/10/2013 10:28:30 AM PDT by illiac (If we don't change directions soon, we'll get where we're going)
[ Post Reply | Private Reply | To 1 | View Replies]

To: Red Badger

That’s what I use to keep rabbits out of the garden.


4 posted on 04/10/2013 10:29:33 AM PDT by cripplecreek (REMEMBER THE RIVER RAISIN!)
[ Post Reply | Private Reply | To 1 | View Replies]

To: illiac
Microprocessors are going Green!


5 posted on 04/10/2013 10:32:02 AM PDT by mbarker12474 (If thine enemy offend thee, give his childe a drum.)
[ Post Reply | Private Reply | To 3 | View Replies]

To: cripplecreek

A Germanium Shepard would work........


6 posted on 04/10/2013 10:34:15 AM PDT by Red Badger (Want to be surprised? Google your own name......Want to have fun? Google your friend's names........)
[ Post Reply | Private Reply | To 4 | View Replies]

To: Red Badger
The problem with germanium was that its oxides are soluble in water thus making integrated circuit creation difficult, while silicon dioxide wasn't so you could easily rinse the silicon wafers during production. I guess since they are dealing with layers one atom thick they don't have an oxidation step to produce an insulating layer and don't have to worry about washing it away.
7 posted on 04/10/2013 10:35:00 AM PDT by KarlInOhio (Choose one: the yellow and black flag of the Tea Party or the white flag of the Republican Party.)
[ Post Reply | Private Reply | To 1 | View Replies]

To: KarlInOhio

The forward voltage drop for a germanium diode is about 0.3-0.4 volts, as opposed to silicon diodes 0.6-0.8 volts. Therefore logic devices could now be designed to use much lower voltages, even below a volt......


8 posted on 04/10/2013 10:37:35 AM PDT by Red Badger (Want to be surprised? Google your own name......Want to have fun? Google your friend's names........)
[ Post Reply | Private Reply | To 7 | View Replies]

To: Red Badger

“Researchers at The Ohio State University...”

Or is it “Researchers at Ohio State University...”


9 posted on 04/10/2013 10:39:00 AM PDT by Rennes Templar
[ Post Reply | Private Reply | To 1 | View Replies]

To: illiac

I suffer the same affliction and I was way off the mark. My thought was ...that will be real lumpy.


10 posted on 04/10/2013 10:41:28 AM PDT by WinMod70
[ Post Reply | Private Reply | To 3 | View Replies]

To: Rennes Templar
Proper name is "The Ohio State University".
11 posted on 04/10/2013 10:44:04 AM PDT by ArrogantBustard (Western Civilization is Aborting, Buggering, and Contracepting itself out of existence.)
[ Post Reply | Private Reply | To 9 | View Replies]

To: illiac
Because of all the water in them geraniums are conductors instead of semiconductors.
12 posted on 04/10/2013 10:49:38 AM PDT by KarlInOhio (Choose one: the yellow and black flag of the Tea Party or the white flag of the Republican Party.)
[ Post Reply | Private Reply | To 3 | View Replies]

To: ArrogantBustard
Proper name is "The Ohio State University".

Learn something everyday.

13 posted on 04/10/2013 10:52:16 AM PDT by eddie willers
[ Post Reply | Private Reply | To 11 | View Replies]

To: rdb3; Calvinist_Dark_Lord; Salo; JosephW; Only1choice____Freedom; amigatec; stylin_geek; ...

14 posted on 04/10/2013 10:53:04 AM PDT by ShadowAce (Linux -- The Ultimate Windows Service Pack)
[ Post Reply | Private Reply | To 1 | View Replies]

To: Rennes Templar

I can assure you that the “The” is a very important part of the name.


15 posted on 04/10/2013 10:54:58 AM PDT by ShadowAce (Linux -- The Ultimate Windows Service Pack)
[ Post Reply | Private Reply | To 9 | View Replies]

To: Red Badger

“The forward voltage drop for a germanium diode is about 0.3-0.4 volts, as opposed to silicon diodes 0.6-0.8 volts. Therefore logic devices could now be designed to use much lower voltages, even below a volt......”


Yes, RB if that characteristic remains true with this different format then lower voltage devices would be in the wings. One atom thick, hard to get any device thinner that that unless they can get the tinny hydrogen atom to do some semiconductor tricks.


16 posted on 04/10/2013 11:07:58 AM PDT by Wurlitzer (Nothing says "ignorance" like Islam!)
[ Post Reply | Private Reply | To 8 | View Replies]

To: Red Badger
You, know... I wonder if we're just finding that a lot of materials, when an atom thick, show phenomenal properties.

I wonder what happens if one uses Tin, Lead, Iron, Copper, etc.? Are similar unusual effects found?

17 posted on 04/10/2013 11:15:29 AM PDT by Freeport (The proper application of high explosives will remove all obstacles.)
[ Post Reply | Private Reply | To 1 | View Replies]

To: eddie willers

“Proper name is “The Ohio State University”.

Learn something everyday.”

It’s the only thing football players learn there, so they can properly identify their farm team when introduced on Monday Night Football.


18 posted on 04/10/2013 11:22:14 AM PDT by henkster (I have one more cow than my neighbor. I am a kulak.)
[ Post Reply | Private Reply | To 13 | View Replies]

To: Wurlitzer

In its solid state, hydrogen is a metal...........


19 posted on 04/10/2013 11:37:20 AM PDT by Red Badger (Want to be surprised? Google your own name......Want to have fun? Google your friend's names........)
[ Post Reply | Private Reply | To 16 | View Replies]

To: henkster
It’s the only thing football players learn there,....

It’s the only thing football players learn there, so they know which bus to get on after the games.......

20 posted on 04/10/2013 11:38:17 AM PDT by Red Badger (Want to be surprised? Google your own name......Want to have fun? Google your friend's names........)
[ Post Reply | Private Reply | To 18 | View Replies]

To: ShadowAce
I can assure you that the “The” is a very important part of the name.

Because its easier to spell than "OHIO"?


21 posted on 04/10/2013 12:22:39 PM PDT by eddie willers
[ Post Reply | Private Reply | To 15 | View Replies]

To: Red Badger

SiGe is already being used in RF chips so the chip makers have some experience working with it already.


22 posted on 04/10/2013 12:26:07 PM PDT by Straight Vermonter (Posting from deep behind the Maple Curtain)
[ Post Reply | Private Reply | To 1 | View Replies]

To: Red Badger

Wow, another element primarily mined in China, yes other countries mine it however the greatest amount by far comes from China.


23 posted on 04/10/2013 12:56:12 PM PDT by Mastador1 (I'll take a bad dog over a good politician any day!)
[ Post Reply | Private Reply | To 1 | View Replies]

To: Red Badger
Thank, Red Badger! Very interesting.

I had a crystal radio when I was a kid, and was alive when the first transistor was invented.

Had lots of fun with them in school ........................................................................................... FRegards

24 posted on 04/10/2013 1:16:45 PM PDT by gonzo ( Buy more ammo, dammit! You should already have the firearms ... FRegards)
[ Post Reply | Private Reply | To 1 | View Replies]

To: Mastador1

25 posted on 04/10/2013 1:37:48 PM PDT by Red Badger (Want to be surprised? Google your own name......Want to have fun? Google your friend's names........)
[ Post Reply | Private Reply | To 23 | View Replies]

To: Red Badger
The reason the world switched from germanium to silicon was the poor performance at higher temperatures and the large leakage current, which increases power consumption, which increases temperature, which increases power consumption, which....

There might be special-use value here and there, but it ain't going to replace silicon, IMHO.

26 posted on 04/10/2013 2:04:19 PM PDT by expat2
[ Post Reply | Private Reply | To 1 | View Replies]

To: Red Badger

Wow. This has great possibilities.


27 posted on 04/10/2013 2:09:23 PM PDT by Cyber Liberty (I am a dissident. Will you join me? My name is John....)
[ Post Reply | Private Reply | To 1 | View Replies]

To: Red Badger

O - H !


28 posted on 04/10/2013 2:18:19 PM PDT by tang-soo (Prophecy of the Seventy Weeks - Read Daniel Chapter 9)
[ Post Reply | Private Reply | To 1 | View Replies]

Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.

Free Republic
Browse · Search
News/Activism
Topics · Post Article

FreeRepublic, LLC, PO BOX 9771, FRESNO, CA 93794
FreeRepublic.com is powered by software copyright 2000-2008 John Robinson