Nat Mater. 2011 Sep 18;10(11):857-61. doi: 10.1038/nmat3122.
Solar cells based on polycrystalline Cu(In,Ga)Se(2) absorber layers have yielded the highest conversion efficiency among all thin-film technologies, and the use of flexible polymer films as substrates offers several advantages in lowering manufacturing costs. However, given that conversion efficiency is crucial for cost-competitiveness, it is necessary to develop devices on flexible substrates that perform as well as those obtained on rigid substrates. Such comparable performance has not previously been achieved, primarily because polymer films require much lower substrate temperatures during absorber deposition, generally resulting in much lower efficiencies. Here we identify a strong composition gradient in the absorber layer as the main reason for inferior performance and show that, by adjusting it appropriately, very high efficiencies can be obtained. This implies that future manufacturing of highly efficient flexible solar cells could lower the cost of solar electricity and thus become a significant branch of the photovoltaic industry.
基于多晶 Cu(In,Ga)Se(2) 吸收层的太阳能电池在所有薄膜技术中具有最高的转换效率，而使用柔性聚合物薄膜作为衬底在降低制造成本方面具有多项优势。然而，鉴于转换效率对于成本竞争力至关重要，因此有必要在柔性衬底上开发性能与在刚性衬底上获得的性能相当的器件。以前没有实现这种可比的性能，主要是因为聚合物薄膜在吸收层沉积过程中需要更低的衬底温度，通常导致效率更低。在这里，我们确定吸收层中的强成分梯度是性能较差的主要原因，并表明通过适当调整可以获得非常高的效率。这意味着未来高效柔性太阳能电池的制造可以降低太阳能电力的成本，从而成为光伏产业的一个重要分支。
