Is there anything that lasers can't do? The latest breakthrough comes from a team of researchers at Nanyang Technological University (NTU) who have developed a method for cooling semiconductor material (cadmium sulfide) with lasers. In an article published in Nature, NTU reserachers report on cooling a semiconductor from 20 degrees C (68 degrees F) to -20 degrees C (-4 degrees F) as an initial proof of concept.

Heat is an unwanted side effect of most energy-using devices. In many cases, ranging from portable electronics to medical magnetic resonance imagery equipment to scientific research equipment, the need for keeping the equipment cooled is vital to continued function. At present, equipment such as MRI systems require liquid helium for cooling, but with laser cooling, the system could be made smaller and would not require the extensive cooling hardware that is currently needed.

Cooling gasses with lasers is a known technology, but cooling a solid has not been done previously, although the theory behind it is decades old. "Our initial results published in Nature, have shown that it is possible to laser-cool a semiconductor to liquid nitrogen temperature, so we are aiming to reach an even lower temperature, such as that of liquid helium," said Prof Xiong Qihua, a member of the NTU team.

Other cooling technologies for computers have been proposed which could lead to significant energy savings. But if laser cooling eventually became widely used for other applications, it would make this even more beneficial. Laser cooled equipment could be more energy efficient, and portable electronic equipment with this technology would also potentially prolong battery life.

In addition to the energy benefits, wide-scale development and application of this technology would also drastically reduce the amount of refrigerants needed in industry and technology. Many of the chemicals used in refrigeration equipment are harmful to the Earth's ozone layer or have a significant global warming potential (and many are both). Reducing the need for these chemicals would be an added benefit laser cooling might someday offer.

image: CC BY 2.0 by Jeff Keyzer/Wikimedia Commons

via: Science Daily

Another development to improve the efficiency of solar panels has been announced by researchers from Princeton University led by professor Stephen Chou. By using a nanostructured "sandwich" of metal and plastic, the efficiency of thin film solar collectors was improved by 175 percent.

The nanoscale lattice on top of the sandwich is able to trap light with openings called a "plasmonic cavity with subwavelength hole array" or PlaCSH. The layer is made of gold and is only 30 nanometers thick. Each hole is 175 nanometers in diameter and spaced 25 nanometers apart. The opening is smaller than the wavelength of light, which traps it rather than allowing it to reflect off the collector, which leads to improved conversion of light to electricity.

The mesh layer also replaces the indium-tin-oxide (ITO) layer which is typically on top of thin-film solar cells, which is one of the most expensive parts of these cells. The ITO layer is also more brittle, while the PlaCSH is extremely bendable.

image credit: Chou lab

via: Phys Org