卤化铅可用作新式太阳能电池的原材料_英语科普

卤化铅可用作新式太阳能电池的原材料

文章来源：未知文章作者：enread 发布时间：2014-01-23 06:50 字体： [大中小]　进入论坛

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Photovoltaic（光电的） energy conversion¹ offers one of the best means for the future of renewable energy in the world. The efficiency of solar cells depends heavily upon the light-absorbing materials they use. Photovoltaic systems based on lead halide perovskite are a new, revolutionary type of device with efficiencies currently exceeding 16%. However, a detailed² description of how these solar cells turn light into electrical current is still lacking. Publishing in Nature Photonics, scientists from EPFL have investigated how the generated electrical charge travels across the perovskite（钙钛矿） surface of solar cells built with different architectures. Lead halide perovskites are materials that have recently attracted an immense interest, as solar cells based on these semiconductors⁴ demonstrate very high conversion efficiencies and an unsurpassed cell voltage of more than 1 V. However, it is not entirely⁵ clear how they work. A better understanding of their functioning mechanisms⁶ would help improve them in the future or even open up novel technologies with increased efficiency.

The groups of Michael Grätzel and Jaques E. Moser at EPFL, working with the Institute for Solar Fuels in Berlin, have used time-resolved spectroscopy techniques to determine how charges move across perovskite surfaces. The researchers worked on various cell architectures, using either semiconducting titanium dioxide or insulating aluminum⁸ trioxide films. Both porous⁹（多孔的） films were impregnated with lead iodide perovskite (CH3NH3PbI3) and an organic "hole-transporting material," which helps extracting positive charges following light absorption. The time-resolved techniques included ultrafast laser spectroscopy and microwave photoconductivity.

The results showed two main dynamics¹⁰. First, that charge separation, the flow of electrical charges after sunlight reaches the perovskite light-absorber, takes place through electron transfer at both junctions¹¹ with titanium dioxide and the hole-transporting material on a sub-picosecond timescale. Secondly¹², the researchers found that charge recombination was significantly slower for titanium oxide⁷ films rather than aluminum ones. Charge recombination is a detrimental¹³ process wasting the converted energy into heat and thus reducing the overall efficiency of the solar cell.

The authors state that lead halide perovskites constitute unique semiconductor³ materials in solar cells, allowing ultrafast transfer of electrons and positive charges at two junctions simultaneously¹⁴ and transporting both types of charge carriers quite efficiently¹⁵. In addition, their findings show a clear advantage of the architecture based on titanium dioxide films and hole-transporting materials.

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收听单词发音

1 conversion
n.转化，转换，转变
参考例句：
He underwent quite a conversion.他彻底变了。 Waste conversion is a part of the production process.废物处理是生产过程的一个组成部分。

2 detailed
adj.详细的，详尽的，极注意细节的，完全的
参考例句：
He had made a detailed study of the terrain.他对地形作了缜密的研究。 A detailed list of our publications is available on request.我们的出版物有一份详细的目录备索。

3 semiconductor
n.半导体
参考例句：
In the beginning,engineers hoped to use semiconductor lasers.在开始时，工程师们希望能够利用半导体激光器。 The main agent of the company brand semiconductor sales.本公司主要代理各品牌半导体销售。

4 semiconductors
n.半导体( semiconductor的名词复数 )
参考例句：
Crystals may be insulators, semiconductors, or conductors. 晶体可以是绝缘体，半导体，或导体。来自辞典例句 Semiconductors containing such impurities are called p-type semiconductors. 含有这类杂质的半导体叫做P型半导体。来自辞典例句

5 entirely
ad.全部地，完整地；完全地，彻底地
参考例句：
The fire was entirely caused by their neglect of duty. 那场火灾完全是由于他们失职而引起的。 His life was entirely given up to the educational work. 他的一生统统献给了教育工作。

6 mechanisms
n.机械( mechanism的名词复数 )；机械装置；[生物学] 机制；机械作用
参考例句：
The research will provide direct insight into molecular mechanisms. 这项研究将使人能够直接地了解分子的机理。来自《简明英汉词典》 He explained how the two mechanisms worked. 他解释这两台机械装置是如何工作的。来自《简明英汉词典》

7 oxide
n.氧化物
参考例句：
Oxide is usually seen in our daily life.在我们的日常生活中氧化物很常见。 How can you get rid of this oxide coating?你们该怎样除去这些氧化皮？

8 aluminum
n.(aluminium)铝
参考例句：
The aluminum sheets cannot be too much thicker than 0.04 inches.铝板厚度不能超过0.04英寸。 During the launch phase,it would ride in a protective aluminum shell.在发射阶段，它盛在一只保护的铝壳里。

9 porous
adj.可渗透的，多孔的
参考例句：
He added sand to the soil to make it more porous.他往土里掺沙子以提高渗水性能。 The shell has to be slightly porous to enable oxygen to pass in.外壳不得不有些细小的孔以便能使氧气通过。

10 dynamics
n.力学，动力学，动力，原动力；动态
参考例句：
In order to succeed,you must master complicated knowledge of dynamics.要取得胜利，你必须掌握很复杂的动力学知识。 Dynamics is a discipline that cannot be mastered without extensive practice.动力学是一门不做大量习题就不能掌握的学科。

11 junctions
联结点( junction的名词复数 )；会合点；（公路或铁路的）交叉路口；（电缆等的）主结点
参考例句：
Metals which were mutually soluble would tend to give strong junctions. 可互溶的金属趋向于产生牢固的结合点。 Some adhering junctions are present as narrow bands connecting two cells. 有些粘附连接以一窄带的形式连接两个细胞。

12 secondly
adv.第二，其次
参考例句：
Secondly,use your own head and present your point of view.第二，动脑筋提出自己的见解。 Secondly it is necessary to define the applied load.其次，需要确定所作用的载荷。

13 detrimental
adj.损害的，造成伤害的
参考例句：
We know that heat treatment is detrimental to milk.我们知道加热对牛奶是不利的。 He wouldn't accept that smoking was detrimental to health.他不相信吸烟有害健康。

14 simultaneously
adv.同时发生地，同时进行地
参考例句：
The radar beam can track a number of targets almost simultaneously.雷达波几乎可以同时追着多个目标。 The Windows allow a computer user to execute multiple programs simultaneously.Windows允许计算机用户同时运行多个程序。

15 efficiently
adv.高效率地，有能力地
参考例句：
The worker oils the machine to operate it more efficiently.工人给机器上油以使机器运转更有效。 Local authorities have to learn to allocate resources efficiently.地方政府必须学会有效地分配资源。