Excitation of guided-mode resonances in thin film silicon solar cells
Excitation of guided-mode resonances in thin film silicon solar cells
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薄膜硅太阳能电池中导模谐振的激发
DOI：
10.1557/opl.2011.946
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
C. Ballif
中科院分区：
文献类型：
--
作者：
F. Haug;K. Söderström;A. Naqavi;C. Ballif
薄膜硅太阳能电池在光伏领域具有很大的吸引力，但这种材料的电荷传输性能较差，这就要求器件的厚度必须小于吸收长度。然而，通过纹理界面上的光散射可以实现足够的吸收，因为如果光被散射到超过全内反射临界角的角度，则可以被困在吸收器层内。这种情况可以用导模在波导中的传播来识别，其中硅扮演高折射率导波介质的角色，而界面织构通过光栅耦合将入射光耦合到模。我们提出了一种在线栅上实现太阳电池结构的实验方法，其中增强的光电流可以清楚地与波导模的共振激发相关联。
Thin film silicon solar cells are attractive for photovoltaics; however, the poor charge transport in this material requires that the devices are thinner than the absorption length. Adequate absorption can nevertheless be achieved by light scattering at textured interfaces because light can get trapped inside the absorber layer if it is scattered into angles above the critical angle of total internal reflection. This situation can be identified with the propagation of a guided mode in a waveguide where silicon plays the role of the high index guiding medium and the interface texture serves to couple the incident light to modes via grating coupling. We present an experimental realization of a solar cell structure on a line grating where the enhanced photocurrent can be clearly related to resonant excitation of waveguide modes.