一種成本更低的太陽能光伏電池
The Brilliant Idea: A solar cell that requires only a fraction ofthe silicon used in standard PV.
一項(xiàng)杰出的發(fā)明:一種所需要的硅材料僅僅是當(dāng)今傳統(tǒng)硅基太陽能電池一小部分的太陽能電池.
Innovators: Harry Atwater, Michael Kelzenberg, Nathan Lewis,California Institute of Technology
***:哈利 阿特霍特，邁克 克爾澤伯格， 內(nèi)森 劉易斯，加州理工大學(xué)
Chemist Harry Atwater’s gift for manipulating light has led tosome eye-opening innovations, including an “invisibility cloak.”His most recent feat: reinventing the solar cell.
化學(xué)家哈利 阿特霍特對(duì)于如何利用光的研究帶來了一些很有啟發(fā)的新發(fā)明，其中包括所謂的“隱身斗篷”。他*近的一項(xiàng)貢獻(xiàn)則是發(fā)明了一種新型的太陽能電池。
More than half of the silicon acting as a semiconductor instandard photovoltaic (PV) panels—made of wafers—winds up asshavings on the factory floor. Atwater’s team at Caltech wastesvirtually nothing, instead growing silicon microwires using vapordeposition. (Picture a tiny bed of nails growing out of a cloud ofsilicon-rich gas.) Researchers coat the microwires with alight-absorbing material, then embed them, along withlight-scattering particles, in a clear polymer that has areflective backing. As light pours in, it bounces around until 90percent has been absorbed.
當(dāng)今傳統(tǒng)的光伏器件(太陽能電池板)有一半以上是以硅這種半導(dǎo)體材料為基礎(chǔ)的，它們都是用硅晶片制成的，整個(gè)過程類似于在工廠車間里對(duì)硅片進(jìn)行“刨???和修飾”（當(dāng)然事實(shí)上是個(gè)較復(fù)雜的過程，包含各種化學(xué)物理工藝過程）。加州理工的阿特霍特的團(tuán)隊(duì)利用了氣相沉積的方法在基底上生長(zhǎng)了一種極細(xì)的硅絲來替代傳統(tǒng)的硅晶片，這種方法幾乎沒有原材料的浪費(fèi)。(如圖所示一個(gè)小基底位于富硅氣體環(huán)境中其上方長(zhǎng)出許多釘狀硅晶體）。研究者們?cè)谶@些極細(xì)的硅絲的上方沉積一層光吸收材料，然后把它們和一些能夠散射光的微粒一起嵌入一個(gè)底部有一層反射層的透明聚合物。當(dāng)光入射的時(shí)候，由于其內(nèi)部結(jié)構(gòu)的原因，大約90%的光線都被吸收。
The wire arrays require only 1 percent of the silicon—whichaccounts for roughly half of the manufacturing costs—of standardPV. The first tests of the technology at scale converted light intoelectricity at a rate of 8 percent, which the team is convinced itcan double (standard PV has 20 percent efficiency). Plus, the cellsare flexible enough to be applied to roof shingles or curtainwalls. “They have the photovoltaic properties of conventional solarcells but the mechanical properties of a plastic bag,” Atwatersays.
這種利用微細(xì)硅絲的光伏組件中硅的實(shí)際含量大約只有1%，正是這個(gè)原因?qū)е铝苏麄€(gè)制造的成本大約只有傳統(tǒng)硅基光伏產(chǎn)業(yè)的一半。**測(cè)試這種新技術(shù)的光電轉(zhuǎn)換效率達(dá)到了8%，并且該團(tuán)隊(duì)相信不久的將來其效率能夠翻倍（傳統(tǒng)的硅基太陽能電池的光電轉(zhuǎn)換效率在20%左右,事實(shí)上單節(jié)的單晶硅基電池實(shí)驗(yàn)室*高能達(dá)到26%左右，商業(yè)應(yīng)用的大概18%左右)。更加值得一提的是，由于此種新型電池的柔韌特性，使得它有望應(yīng)用于屋頂?shù)耐咂匣蚴谴昂焿ι希▊鹘y(tǒng)的硅基電池板柔軟度和重量都受限）。就像阿特霍特所說“這種電池具備了太陽能電池的光伏特性的同時(shí)也具備了塑料袋的機(jī)械特性（像塑料袋一樣柔軟輕便）。”