Kowalczewski Piotr, Liscidini Marco, Andreani Lucio Claudio
Opt Express. 2013 Sep 9;21 Suppl 5:A808-20. doi: 10.1364/OE.21.00A808.
We study light-trapping in thin-film silicon solar cells with rough interfaces. We consider solar cells made of different materials (c-Si and μc-Si) to investigate the role of size and nature (direct/indirect) of the energy band gap in light trapping. By means of rigorous calculations we demonstrate that the Lambertian Limit of absorption can be obtained in a structure with an optimized rough interface. We gain insight into the light trapping mechanisms by analysing the optical properties of rough interfaces in terms of Angular Intensity Distribution (AID) and haze. Finally, we show the benefits of merging ordered and disordered photonic structures for light trapping by studying a hybrid interface, which is a combination of a rough interface and a diffraction grating. This approach gives a significant absorption enhancement for a roughness with a modest size of spatial features, assuring good electrical properties of the interface. All the structures presented in this work are compatible with present-day technologies, giving recent progress in fabrication of thin monocrystalline silicon films and nanoimprint lithography.
我们研究具有粗糙界面的薄膜硅太阳能电池中的光捕获。我们考虑由不同材料（晶体硅和微晶硅）制成的太阳能电池，以研究能带隙的大小和性质（直接/间接）在光捕获中的作用。通过严格的计算，我们证明在具有优化粗糙界面的结构中可以达到朗伯吸收极限。通过根据角强度分布（AID）和雾度分析粗糙界面的光学特性，我们深入了解了光捕获机制。最后，通过研究一种混合界面（它是粗糙界面和衍射光栅的组合），我们展示了合并有序和无序光子结构用于光捕获的好处。对于具有适度空间特征尺寸的粗糙度，这种方法能显著提高吸收，同时确保界面具有良好的电学性能。这项工作中展示的所有结构都与当今技术兼容，这在薄单晶硅膜的制造和纳米压印光刻方面取得了最新进展。
