论文标题
安德森绝缘子中的转移电流理论
Theory of shift current in Anderson insulator
论文作者
论文摘要
移位电流是散装非中心绝缘体中的光伏电流。迄今为止，对移位电流的研究集中在扩展的BLOCH波上，例如半导体和钙钛矿。相反，尚不清楚局部波函数是否支持直流光电流。在这里，我们从理论上表明，直流移电流出现在具有随机电势的非中心疾病的一维绝缘子中。当光照明整个样品时，在存在电子偶联的情况下形成光电流。我们发现，即使随机电势的能量尺度大于带宽，这种光电流仍然坚固。另一方面，当激发在局部时，光电流呈指数衰减，或者放松仅是由于与电极的接触。这些结果为设计高效率太阳能电池和光电探测器开辟了途径。
Shift current is a photovoltaic current in bulk noncentrosymmetric insulator. Studies on shift current have so far focused on the extended Bloch waves, such as in semiconductors and perovskites. In contrast, it is unknown whether the localized wavefunctions support the dc photocurrent. Here, we show theoretically that the dc shift current appears in a noncentrosymmetric disordered one-dimensional insulator with random potential. When the light illuminates the entire sample, the photocurrent forms in presence of the electron-phonon coupling. We find this photocurrent remains robustly even when the energy scale of random potential is larger than the bandwidth. On the other hand, the photocurrent decays exponentially when the excitation is local, or the relaxation is only due to the contact with the electrodes. These results open a route to design high-efficiency solar cells and photodetectors.
