经济学人下载:光电池 利用染料进行能量转化

Science and technology.
科技。

Photoelectric cells.
光电池。

To dye for.
利用染料进行能量转化。

A new type of cell may bring "solar" energy indoors.
一种新型电池也许能带来室内"太阳能"。

THE phrase "indoor solar power" sounds like an oxymoron. But there is growing interest in the idea of using photoelectric cells to run gadgets as well as power grids-and doing so even when those gadgets are inside buildings. Much of the light these cells used would, of necessity, come from incandescent bulbs, fluorescent tubes and light-emitting diodes (LEDs) rather than through the window from the sun. But if the right sorts of cells were available this could be cheaper than constantly replacing the batteries that currently power electronic gizmos.
"室内太阳能"这个词听起来有点儿自相矛盾,可科学家们对于利用光电池来驱动用电装置和电网越来越感兴趣了—这些光电池即使在室内也能够正常工作。它们所利用的光能中的大部分势必来自白炽灯，日光灯和发光二极管，而并非透过窗户照射进来的太阳光。不过一旦某种特殊的光电池被研发出来，相比于通过频繁更换电池为用电装置供电的传统方式，新型光电池的应用将能够大大降低成本。

On April 8th G24 Innovations, a firm based in Wales, announced that it may have come up with just such a cell. The latest version of its special, dye-based photoelectric devices has set a new record for the conversion of light from bulbs into electricity: an efficiency of 26%, compared with the 15% which previous ones can manage. That lifts dye-based cells to the point where they might be widely deployable for indoor power.
在四月八日，一个总部位于威尔士的公司——G24 Innovations宣布他们已经开发出这种光电池。它的独特之处在于其基于染料的光电转化设置，该装置最新版本的转化效率已经从上一代的15%提高到创纪录的26%。这大大增加了将该类型电池应用于室内供电领域的可能性。

Dye-based cells are similar to the silicon-based variety found on rooftops around the world in that both rely on a semiconductor to assist the conversion of luminous energy into the electrical sort. The difference is that in the case of silicon cells, this conversion happens directly. That means the frequency of light absorbed is constrained by the physical properties of silicon itself.
这种基于染料的光电池同另外一种基于硅的光电池——如今已在全世界广泛应用，与屋顶随处可见——比较相似，它们的光电转换都依赖于一种半导体。不同之处在于硅型光电池的光电转化过程是直接进行的。这意味着被吸收的光的频率将受限于硅自身的物理性质。

In the case of dye-based cells, which were invented at the Federal Polytechnic School of Lausanne, in Switzerland, in the 1990s, the light is first captured by molecules of a photosensitive dye. Tinker with the composition of this dye and you change the frequency of light that can be captured. This makes dye-based cells more flexible than silicon ones.
至于染料型光电池，它们在二十世纪九十年代发明于瑞士洛桑的联合工艺培训学校，是利用光敏染料分子将光捕获。若要捕获不同频率的光，只需对染料的成分进行调整。因此染料型光电池使用起来比硅型光电池更为灵活方便。

The dye molecules themselves are bound to tiny particles of titanium dioxide, a less-famous (but cheaper) semiconductor than silicon, and the whole assembly is immersed in an electrolyte and sandwiched between two electrodes. When a photon of light is absorbed by a dye molecule, an electron is knocked into the titanium dioxide. From there it travels to one of the electrodes and a current is thus generated.
染料分子自身会与二氧化钛（一种不如硅名气大，但比硅便宜的半导体）的细小微粒相结合，然后整个装置会浸没于一种电解质里并夹于两个电极之间。当一个光子被一个染料分子所吸收，就会有一个电子被击入二氧化钛，这些电子会从二氧化钛中流入其中一个电极，从而产生了电流。

The flexibility brought by the dye-based approach makes this sort of cell particularly useful indoors. Silicon-based solar cells have been optimised for sunlight. But artificial light, whether of the incandescent, fluorescent or LED variety, contains a different mixture of frequencies from that put out by the sun. By changing the composition of the dye, G24's engineers ensure that the maximum sensitivity of the cell coincides with whatever frequency mix is appropriate for the artificial light concerned.
染料型光电池的这种灵便性使其能在室内发挥很大作用。硅型光电池是面向于太阳光的，而对于各种人造光源，无论是白炽灯，日光灯还是LED灯，它们发出的光的混合了多种频率，且与太阳光的不同。（为了利用人造光源的光能，）G24的工程师们通过改变染料的成分确保光电池的最大灵敏度区域契合于人造光源所发出的光的混合频率。

Besides being tweakable to match the spectrum of a light-bulb, dye-based cells also work well in dim or diffuse light of the sort often found indoors. Silicon-based systems do not. And dye-based cells, having no rigid parts, can bend, and are mechanically robust compared with the silicon sort. That gives them a further advantage over silicon cells, especially for powering consumer gadgets.
除了能根据灯泡光的光谱对吸光性能进行微调外，即使是在常见于室内的昏暗或漫射的光照情况下，染料型光电池也能够正常工作。这个优点是硅型光电池所不具备的。而且染料型光电池全由非刚性材料构成，可弯可折，与硅型光电池相比其机械强度更高。这使得它们比硅型光电池又多了一项优势，尤其是在消费电子类产品供电领域。

Steven Burt, G24's chief financial officer, talks of light-bulb-powered TV remote controls, smoke detectors and computer keyboards. (A non-removable internal battery would store charge for use when the lights are off.) The company already offers prototypes of bags and jackets with photosensitive panels woven in, designed to charge digital cameras and mobile phones, and a hotel in Las Vegas is using G24's products to run its electric window-blinds. Mr Burt also sees a market for powering the networks of sensors needed to monitor things like temperature and humidity in modern "smart" buildings.
G24的财务总监——Steve Burt谈到可用灯泡光进行供电的有电视遥控器，烟雾检测器和电脑键盘（无灯光时其内置的电池会发挥作用）。这家公司已经开始提供袋子和夹克的样品，其中被缝入了光敏夹板，按照设计理念将可为数码相机和手机充电，此外一家拉斯维加斯的酒店正在使用G24的产品来运行其电动窗帘。而在另一片市场——智能建筑中构成监测网络的温度，湿度等传感器供电领域中，Burt同样看到了公司产品不错的应用前景。

Eventually, says Mr Burt, the ability of dye-based cells to produce useful quantities of power even in dim and diffuse light could see them used outside, perhaps on rooftops in cloudier parts of the world-a market at present dominated by traditional, silicon-based cells, even though they are not well-suited to the purpose. But for now, G24's factory in Cardiff, not a city known for its sunshine, remains powered by a wind turbine.
染料型光电池在昏暗光或漫射光的照射条件下依然能够产生数量可观的电能，Burt先生认为这项能力将会促使其在室外的推广应用，也许可以安装在多云天气区域的建筑物屋顶上（目前这片市场中占统治地位的还是传统的硅型光电池，虽然效果并不太突出）。不过直到现在，G24设在加的夫（这可不是一个阳光充足的城市）的工厂仍是由风力发电机供电。