Solar's new power (Part.03)

Not all perovskites are semiconductors. But a group based on a metal, such as tin, and a halogen, such as chlorine, bromine or iodine, do have that property. The ingredients of these metal-halide perovskites are, moreover, abundant and inexpensive. One of the leaders in the field of making cells out of them is Oxford PV, a British firm founded in 2010 to exploit work done on perovskites by Henry Snaith of Oxford University. The firm’s design is a hybrid structure, known as a tandem cell, that coats a silicon layer with perovskite.

• tin
  • 锡
• halogen
  • 卤素
• bromine
  • 溴
• iodine
  • 碘
• ingredient
  • a component of a mixture, compound, etc, esp in cooking 成分，（尤指烹饪）材料
• halide
  • 卤化物
• moreover
  • 此外，而且
• exploit
  • 运用，利用，发挥；开拓，开采
• hybrid
  • 混合物，合成物；杂种
• tandem
  • working or occurring in conjunction with each other 串联的
  • 双人自行车

This brings two advantages. One is that, like a multilayered Ⅲ-Ⅴ cell, a perovskite-sillicon tandem cell divides up the job of capturing sunlight. The upper, perovskite, layer is tweaked to absorb light from the blue end of the spectrum. The lower, silicon, layer mops up the remaining wave-lengths towards the red end. This makes for high efficiency. In a test in 2018 such a tandem cell set a new record for its type with an efficiency of 28%. Eventually, the firm’s engineers think, they can push this into the “mid-30s”.

• tweak
  • 稍稍调整（机器、系统等）
• mop sth ↔ up
  • 完成，结束（最后部分）；收尾
• set a new record
  • 创新记录

The second advantage of piggybacking the perovskite on silicon is that the cells are fairly easy to make into solar panels using standard industrial processes. That helps keep them competitive with conventional solar panels. A new factory that will do just this is currently under construction in Germany. The hope is that─the pandemic provided─the first panels made in this plant will go on sale next year.

• piggyback
  • to attach to or mount on (an existing piece of equipment or system) 将……增加到（已经存在的东西上）
  • [noun] 肩驮，驮运
• solar panel
  • 太阳能电池板
• conventional
  • 传统的

Whether an efficiency in the mid-30s will be enough to displace silicon cells from part of their existing market remains to be seen. Perovskites may, however, have applications doing jobs that silicon cannot manage. For instance, they work well in low light intensities. This has permitted a group led by Thomas Brown of Tor Bergata University of Rome and John Fahlteich of the Fraunhofer Institute’s campus in Dresden, Germany, to develop versions which operate at the levels of illumination found inside buildings. The amount of energy in artificial lighting is vastly less than that in sunshine. Nevertheless, Dr Brown and Dr Fahlteich have found, according to a paper they published this month in Cell Reports Physical Science, that their cells can achieve a conversion efficiency of up to 22.6% thereby producing enough juice to run small, low-power devices like wireless sensors and remote-control units, which would otherwise require batteries.

• intensity
  • the strength of sth, for example light, that can be measured 强度，烈度
• vastly
  • very much 非常，很
• nevertheless
  • despite sth that you have just mentioned 尽管如此，然而
• conversion
  • 转换，转变
• juice
  • (informal) electricity 电

Though it may seem odd to turn artificial, indoor lighting into electricity, given that it has been created from electricity in the first place, the truth is that all such light which does not end up entering a human eye is wasted. This approach simply reduces the level of waste. With the growth of the so-called internet of things, which relies on many different types of sensors, wireless control systems and other bits of electronic kit, such an approach could have wide application. If it works, the label “batteries not included” will go from being a warning to a recommendation.

• given
  • [preposition] 考虑到；鉴于
• internet of things
  • 物联网
• bit
  • 小量，小块
• kit
  • 成套工具，成套设备