交大开元太阳能

Solar power is usually in the most efficient noon, at this time because the sun is at its highest point, 90-degree angle to direct the battery. However, the USA and Georgia Institute of Technology researchers have recently developed a new type of battery on the contrary - the battery in most of the day when all the higher efficiency of the operation, and every morning, afternoon and the highest efficiency. This use of nanotechnology to develop the battery, and solar cells compared to the previous, size, weight and mechanical complexity of the structure are smaller.

According to the USA and Georgia Institute of Technology Web site on April 11 reported that such a laboratory prototype of the battery is only 2 inches small, but every square cm battery contains 40,000 nanotubes "tower", each 100-micron high tower, Base for the long side of 40 square microns, the interval between each 10 microns. Each tower contains millions of vertical array of carbon nanotubes.

       This micro-nano-tube similar to the tower city street grid of high-rise building, its unique three-dimensional structure so that it can capture every angle of the light and enhance the efficiency of power generation. The traditional flat solar cells can only be part of the reflection of light, less energy absorption. The animated show on the site can be seen in the light on after Na Mita in the adjacent tower for reflection on many occasions to increase the rate of absorption of light. Not even in 90-degree sunlight exposure, it can also maintain high efficiency. USA and Georgia Institute of Technology Laboratory of PV systems Jud Ready, a senior engineer, said: "When the sun directly, the interaction of the region is limited to the top and below the 'street'. But when the point of view, have the opportunity to light in the reflective side of the tower. "

       At the same time, this three-dimensional cell to increase the "quantum efficiency" - the battery-photon absorption into the electronic efficiency. In the traditional flat solar cells, the photovoltaic coatings must be thick enough to capture the photons, and then from the e-coating materials have a current release. However, mobile electronics will be behind the atomic matrix to stay in a "hollow." From the electronic materials out longer, the more likely empty and restructuring to reduce the current. As the three-dimensional rather than the traditional cell batteries to absorb more photons, and its corresponding thin coating, electronics can go faster, reducing the chance of reorganization.

       It is reported that the lowest Na Mita is a silicon chip, researchers on the use of photolithography technology has been applied thin layer of iron into a furnace heated to 780 degrees. Hydrocarbon gases pass into the melting pot will be separated into carbon and hydrogen. After chemical vapor deposition process, carbon-coated iron chip in on the deposition, the growth of carbon nanotubes into multi-storey tower. After further research in carbon nanotubes on the tower covered with a layer of cadmium telluride and cadmium sulfide - which is responsible for power generation. In the end, and then coated indium tin oxide - a kind of conductive material - as an electrode. As a result, the battery in the nanotubes, it is not only as a three-dimensional structure of the support frame and connected photovoltaic material as silicon chips and the conductor, responsible for the electronic transfer to the electrodes.

In the application, Ready to look first of all on the space shuttle and satellites to provide power, because the batteries do not need to use specialized tools for mobile machinery position to maintain the face of the sun, reducing weight and complexity. "Machine tool easily damaged in space, it is extremely difficult to repair." Ready said.

       According to the Massachusetts Institute of Technology, "technical review" (Technology Review) magazine on April 17 on-line reported that a 90-degree angle when the sun exposure, this three-dimensional model of the battery is only 3.5 percent of the electricity rate. However, when the light from the other point of exposure, the higher power rates, in particular, 45 degrees, the highest power rates to 7%. In other words, the battery in most of the day when all the higher efficiency of the operation, there are two opportunities to meet the daily maximum - as early as the first, the first night.

       However, the efficiency of the use of commercial or too low. Ready said that in the next two years, he will increase the size of the model, a series of tests to ensure that the batteries can launch a rocket and space of the bad environment. Ready would like to come up with the best high tower and away from the tower, as well as their location and angle of the light. He will also try to use other semiconductor materials to replace cadmium telluride, which is considered toxic and not suitable for a wide range of commercial use. To choose the best application of different optical materials research is one of the goals. If all goes well, Ready estimated that 5-10 years, some version of this technology is likely to achieve the commercial application.

"Our objective is to get each piece of the battery can be used photon." Ready said that as more able to capture light, can reduce the size of the battery, satellite or space shuttle, the new battery to reduce weight, occupy less space . Increase the efficiency of power generation, can change the existing use of solar cells for use in wider areas.