Design principles for shift current photovoltaics.
Design principles for shift current photovoltaics.
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DOI：
10.1038/ncomms14176
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发表时间：
2017-01-25
影响因子：
16.6
通讯作者：
Moore JE
中科院分区：
文献类型：
--
作者：
Cook AM;M Fregoso B;de Juan F;Coh S;Moore JE
虽然传统太阳能电池的基本原理已经被很好地理解，但很少有人关注基于移位电流的光伏设备的效率最大化。通过对有效模型的分析，本文概述了对带隙附近频率的移位电流进行优化的简单设计原则。我们的方法允许我们用几个模型参数来表示带边移动电流，并表明它除了取决于标准带结构外还取决于波函数。我们用我们的方法确定了两类移位电流光伏材料，铁电聚合物薄膜和单层正交单硫族化合物，如GeS，它们显示出迄今为止报道的最大带边响应。此外，探索描述它们的紧密结合模型的参数空间，我们发现光响应率可以超过100 mA W−1。我们的研究结果说明了转换电流光伏电池与传统太阳能电池竞争的巨大潜力。以上带隙光电压可以在具有净极化的材料中实现。在这里，Cook等人计算了从带边位移电流的贡献，并确定了两类位移电流光伏材料，GeS和铁电聚合物薄膜。
While the basic principles of conventional solar cells are well understood, little attention has gone towards maximizing the efficiency of photovoltaic devices based on shift currents. By analysing effective models, here we outline simple design principles for the optimization of shift currents for frequencies near the band gap. Our method allows us to express the band edge shift current in terms of a few model parameters and to show it depends explicitly on wavefunctions in addition to standard band structure. We use our approach to identify two classes of shift current photovoltaics, ferroelectric polymer films and single-layer orthorhombic monochalcogenides such as GeS, which display the largest band edge responsivities reported so far. Moreover, exploring the parameter space of the tight-binding models that describe them we find photoresponsivities that can exceed 100 mA W−1. Our results illustrate the great potential of shift current photovoltaics to compete with conventional solar cells. Above band-gap photovoltage could be achieved in materials with a net polarization. Here, Cook et al. compute the contribution to the shift current from the band edge and identify two classes of shift current photovoltaics materials, GeS and ferroelectric polymer films.