论文标题
磁接近诱发的巨大散装光伏在晶体对称层中
Magnetic Proximity Evoked Colossal Bulk Photovoltaics in Crystalline Symmetric Layers
论文作者
论文摘要
大量光伏(BPV)效应是在光照射下生成静电电流的二阶非线性过程,需要中心对称破碎的系统作为其应用平台。为了在空间中心对称材料中实现可测量的BPV光电流,已经开发了各种方案,例如化学掺杂,结构变形或电偏置。在当前的工作中,我们建议通过范德华界面相互作用(一种无接触式策略)通过磁性接近效应,也打破了中心对称性并产生较大的BPV光电。使用BI2TE3五重奏层作为示例材料,我们表明MNBI2TE4隔层的磁接近产生有限的可调偏移和注入光电流。我们采用小组分析和第一原理计算来评估在线性极化光照射下特定层特异性的移位和注射电流世代。我们发现,在BI2TE3层上定位的磁注射光电传入率可以达到70*108 A/(V2S),因此在中间强度的光线下可以达到0.1 mA/nm的1D线性电流密度。除了电流电流外,我们还将讨论扩展到自旋BPV电流中,从而产生纯净的光电自旋电流。电荷和自旋光电流之间的垂直传播方向表明它们可以在单个材料中单独使用。与先前报道的方法相比,通过范德华界面的磁接近效应并不能显着改变中心对称材料的内在特征(例如BI2TE3),并且可以通过近端磁性构型(MNBI2TE4),Interlayer距离和光极化来轻松实现其操作。
Bulk photovoltaic (BPV) effect, a second order nonlinear process that generates static current under light irradiation, requires centrosymmetric broken systems as its application platform. In order to realize measurable BPV photocurrent in spatially centrosymmetric materials, various schemes such as chemical doping, structural deformation, or electric bias have been developed. In the current work, we suggest that magnetic proximity effect via van der Waals interfacial interaction, a contact-free strategy, also breaks the centrosymmetry and generate large BPV photocurrents. Using the Bi2Te3 quintuple layer as an exemplary material, we show that magnetic proximity from MnBi2Te4 septuple layers yield finite and tunable shift and injection photocurrents. We apply group analysis and first-principles calculations to evaluate the layer-specific shift and injection current generations under linearly polarized light irradiation. We find that the magnetic injection photoconductivity that localized on the Bi2Te3 layer can reach over 70*108 A/(V2s), so that a 1D linear current density on the order of 0.1 mA/nm can be achieved under an intermediate intensity light. In addition to charge current, we also extend our discussions into spin BPV current, giving pure photo-generated spin current. The vertical propagation direction between the charge and spin photocurrents suggest that they can be used individually in a single material. Compared with previously reported methods, the magnetic proximity effect via van der Waals interface does not significantly alter the intrinsic feature of the centrosymmetric material (e.g., Bi2Te3), and its manipulation can be easily achieved by the proximate magnetic configurations (of MnBi2Te4), interlayer distance, and light polarization.