Shen Bing, Wang Peng, Menon Rajesh
Opt Express. 2014 Mar 10;22 Suppl 2:A311-9. doi: 10.1364/OE.22.00A311.
Nanostructures have the potential to significantly increase the output power-density of ultra-thin photovoltaic devices by scattering incident sunlight into resonant guided modes. We applied a modified version of the direct-binary-search algorithm to design such nanostructures in order to maximize the output power-density under oblique-illumination conditions. We show that with appropriate design of nanostructured cladding layers, it is possible for a 10nm-thick organic absorber to produce an average peak power-density of 4 mW/cm² with incident polar angle ranging from -90° to 90° and incident azimuthal angle ranging from -23.5° to 23.5°. Using careful modal and spectral analysis, we further show that an optimal trade-off of absorption at λ~510 nm among various angles of incidence is essential to excellent performance under oblique illumination. Finally, we show that the optimized device with no sun tracking can produce on an average 7.23 times more energy per year than that produced by a comparable unpatterned device with an optimal anti-reflection coating.
纳米结构有潜力通过将入射太阳光散射到共振导模中，显著提高超薄光伏器件的输出功率密度。我们应用了直接二元搜索算法的改进版本来设计此类纳米结构，以便在斜照条件下最大化输出功率密度。我们表明，通过对纳米结构包层进行适当设计，对于一个10纳米厚的有机吸收体，当入射极角范围为-90°至90°且入射方位角范围为-23.5°至23.5°时，有可能产生4 mW/cm²的平均峰值功率密度。通过仔细的模态和光谱分析，我们进一步表明，在不同入射角下，在λ~510 nm处的吸收进行最佳权衡对于斜照下的优异性能至关重要。最后，我们表明，无需太阳跟踪的优化器件每年平均产生的能量比具有最佳抗反射涂层的可比无图案器件多7.23倍。
