Absorption enhancement in nanotextured solar cells with Ge/Si heterostructures
Absorption enhancement in nanotextured solar cells with Ge/Si heterostructures
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DOI：
10.7567/jjap.54.04dr03
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发表时间：
2015-04
影响因子：
1.5
通讯作者：
T. Tayagaki;Yuko Kishimoto;Y. Hoshi;N. Usami
中科院分区：
文献类型：
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作者：
T. Tayagaki;Yuko Kishimoto;Y. Hoshi;N. Usami
为了提高Ge/Si量子点太阳能电池的效率，需要有效的光吸收。在这里，我们数值研究了利用Ge/Si异质结构的双面光子纳米结构对近红外光吸收的影响。在近红外区域中的扩展吸收需要底部纳米结构与没有Ge层的Si膜相比具有增加的周期。这里开发的双面纳米结构展示了在可见光区的反射减少和在近红外区的透射减少，将光电流提高到41.7 mA/cm 2。虽然100 nm厚的Ge层的Yablonovitch极限允许在1100-1500 nm范围内充分吸收超过80%的太阳光，但要达到这一极限，还需要进一步优化我们的双面纳米结构。
Efficient light absorption is required to improve the efficiency of Ge/Si quantum dot solar cells. Here, we numerically investigate the impact of double-sided photonic nanostructures on near-infrared light absorption utilizing Ge/Si heterostructures. Extended absorption in the near-infrared region requires bottom nanostructures with an increased period compared with those of Si films with no Ge layer. The double-sided nanostructure developed here demonstrates both reduced reflection in the visible region and reduced transmission in the near-infrared region, enhancing the photocurrent up to 41.7 mA/cm2. Although the Yablonovitch limit of the 100-nm-thick Ge layer allows sufficient absorption of more than 80% of the solar light in the 1100–1500 nm range to be used, further optimization of our double-sided nanostructures is necessary for this limit to be reached.