Spin–orbit effects on the electronic and optical properties of lead iodide
Spin–orbit effects on the electronic and optical properties of lead iodide
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DOI：
10.1063/5.0146397
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发表时间：
2023-05
影响因子：
4
通讯作者：
Woncheol Lee;Zhengyang Lyu;Zidong Li;P. Deotare;E. Kioupakis
中科院分区：
文献类型：
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作者：
Woncheol Lee;Zhengyang Lyu;Zidong Li;P. Deotare;E. Kioupakis
碘化铅（PbI2）由于其直接带隙和层状晶体结构而引起了人们的广泛兴趣。因此，它已被认为是一种有前途的材料，在原子薄的光电子器件的应用。在这项工作中，我们提出了一个详细的调查自旋轨道耦合（SOC）的影响，产生的电子和光学性质的PbI2的重原子的存在下，使用第一性原理计算的基础上密度泛函理论和多体微扰理论。我们发现，SOC不仅改变了带隙，但也诱导轨道特征的混合，导致在整体的能带结构和载流子的有效质量的显着变化。此外，SOC引起的能带轨道混合导致光学跃迁矩阵元的急剧变化，相应地，吸收光谱。我们的实验测量的吸收光谱验证了计算结果，并证明了SOC的PbI2的光学过程中的重要性。我们的研究结果提供的见解，是重要的潜在用途的PbI2作为可见光电子器件的材料平台。
Lead iodide (PbI2) has gained much interest due to its direct electronic gap in the visible range and layered crystal structure. It has thereby been considered as a promising material for applications in atomically thin optoelectronic devices. In this work, we present a detailed investigation of the effect of spin–orbit coupling (SOC) that arises from the presence of heavy atoms on the electronic and optical properties of PbI2 using first-principles calculations based on density-functional theory and many-body perturbation theory. We find that SOC not only alters the bandgap but also induces the mixing of orbital characters, resulting in a significant change in the overall band structure and charge carrier effective masses. Moreover, the band orbital mixing caused by SOC results in the dramatic change in optical transition matrix elements and, correspondingly, the absorption spectrum. Our experimentally measured absorption spectra validate the calculation results and demonstrate the importance of SOC in the optical processes of PbI2. Our findings provide insights that are important for the potential use of PbI2 as a material platform for visible optoelectronic devices.