A completely new method of manufacturing the smallest structures in electronics could make their manufacture thousands of times quicker, allowing for cheaper semiconductors. The findings have been published in the latest issue of Nature.
Instead of starting from a silicon wafer or other substrate, as is usual today, researchers have made it possible for the structures to grow from freely suspended nanoparticles of gold in a flowing gas.
Behind the discovery is Lars Samuelson, Professor of Semiconductor Physics at Lund University, Sweden, and head of the University's Nanometre Structure Consortium. He believes the technology will be ready for commercialisation in two to four years' time. A prototype for solar cells is expected to be completed in two years.
"When I first suggested the idea of getting rid of the substrate, people around me said 'you're out of your mind, Lars; that would never work'. When we tested the principle in one of our converted ovens at 400°C, the results were better than we could have dreamt of", he says.
"The basic idea was to let nanoparticles of gold serve as a substrate from which the semiconductors grow. This means that the accepted concepts really were turned upside down!"
Since then, the technology has been refined, patents have been obtained and further studies have been conducted. In the article in Nature, the researchers show how the growth can be controlled using temperature, time and the size of the gold nanoparticles.
Recently, they have also built a prototype machine with a specially built oven. Using a series of ovens, the researchers expect to be able to 'bake' the nanowires, as the structures are called, and thereby develop multiple variants, such as p-n diodes.
A further advantage of the technology is avoiding the cost of expensive semiconductor wafers.
"In addition, the process is not only extremely quick, it is also continuous. Traditional manufacture of substrates is batch-based and is therefore much more time-consuming", adds Lars Samuelson.
At the moment, the researchers are working to develop a good method to capture the nanowires and make them self-assemble in an ordered manner on a specific surface. This could be glass, steel or another material suited to the purpose.
The reason why no one has tested this method before, in the view of Professor Samuelson, is that today's method is so basic and obvious. Such things tend to be difficult to question.
However, the Lund researchers have a head start thanks to their parallel research based on an innovative method in the manufacture of nanowires on semiconductor wafers, known as epitaxy – consequently, the researchers have chosen to call the new method aerotaxy. Instead of sculpting structures out of silicon or another semiconductor material, the structures are instead allowed to develop, atomic layer by atomic layer, through controlled self-organisation.
The structures are referred to as nanowires or nanorods. The breakthrough for these semiconductor structures came in 2002 and research on them is primarily carried out at Lund, Berkeley and Harvard universities. The Lund researchers specialise in developing the physical and electrical properties of the wires, which helps create better and more energy-saving solar cells, LEDs, batteries and other electrical equipment that is now an integrated part of our lives.
Lund University: http://www.lu.se
This press release was posted to serve as a topic for discussion. Please comment below. We try our best to only post press releases that are associated with peer reviewed scientific literature. Critical discussions of the research are appreciated. If you need help finding a link to the original article, please contact us on twitter or via e-mail.
The winners of the Society of Biology's third annual photography contest include amazing images of a haunting leopard, an otherworldly spider, and Yellowstone National Park's Grand Prismatic Spring.
Bee colonies in Brisbane are waging war for months on end, according to a new study, and the victorious swarms are taking over the hives of rival species.
Hundreds of thousands of cranes stop in Germany on their way to warmer climates
May, June, August and September have all been record-breaking months
Host Audie Cornish talks with Drew Gronewold, a hydrologist at the National Oceanic and Atmospheric Administration, about why water levels in lakes Superior, Michigan and Huron are rising.
Tornadoes in the United States are increasingly coming in swarms rather than as isolated twisters, according to a study by U.S. government meteorologists published on Thursday that illustrates another trend toward extreme weather emerging in recent years.
Just a few years ago, authors were predicting production would soon hit a peak and then decline. But since then, supplies have surged. So are the forecasters now slapping themselves in the head?
The presence of carnivores, which control herbivore numbers, helps plants without thorny defences thrive, a study of life on the savannah reveals.
The roll-out of cheap energy-saving street lights with a bluish glare has little regard for people or wildlife. There is a better way, says Jeff Hecht
In the Pacific Northwest, the salmon are running. They migrate from the ocean into rivers where they eventually spawn on gravel beds. But on the Washougal River near the border of Washington State and Oregon, Ben Tracy found the Salmon are hitching a ride.