Center for Nanophase Materials Sciences and Department of Physics and Astronomy, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831, USA.
Department of Physics and Astronomy, The University of Toledo, McMaster Hall, 2nd Floor Room 2017, Toledo, Ohio 43606, USA.
Nat Commun. 2016 Jul 27;7:12537. doi: 10.1038/ncomms12537.
The published external quantum efficiency data of the world-record CdTe solar cell suggests that the device uses bandgap engineering, most likely with a CdTexSe1-x alloy layer to increase the short-circuit current and overall device efficiency. Here atom probe tomography, transmission electron microscopy and electron beam-induced current are used to clarify the dependence of Se content on the photoactive properties of CdTexSe1-x alloy layers in bandgap-graded CdTe solar cells. Four solar cells were prepared with 50, 100, 200 and 400 nm-thick CdSe layers to reveal the formation, growth, composition, structure and photoactivity of the CdTexSe1-x alloy with respect to the degree of Se diffusion. The results show that the CdTexSe1-x layer photoactivity is highly dependent on the crystalline structure of the alloy (zincblende versus wurtzite), which is also dependent on the Se and Te concentrations.
已发表的世界纪录级 CdTe 太阳能电池的外量子效率数据表明，该器件采用了能带工程，很可能使用了 CdTexSe1-x 合金层来增加短路电流和整体器件效率。在这里，原子探针层析技术、透射电子显微镜和电子束诱导电流被用于澄清 Se 含量对带隙渐变 CdTe 太阳能电池中 CdTexSe1-x 合金层光活性的依赖关系。制备了四个具有 50、100、200 和 400nm 厚 CdSe 层的太阳能电池，以揭示 CdTexSe1-x 合金的形成、生长、组成、结构和光活性相对于 Se 扩散程度的变化。结果表明，CdTexSe1-x 层的光活性高度依赖于合金的晶体结构（闪锌矿与纤锌矿），这也依赖于 Se 和 Te 的浓度。
