Electronic Properties of Bulk and Monolayer TMDs: Theoretical Study Within DFT Framework (GVJ-2e Method)
Electronic Properties of Bulk and Monolayer TMDs: Theoretical Study Within DFT Framework (GVJ-2e Method)
复制标题
DOI：
10.1002/pssa.201700218
复制
发表时间：
2017-12-01
影响因子：
2
通讯作者：
Tay, Beng Kang
中科院分区：
文献类型：
--
作者：
Gusakova, Julia;Wang, Xingli;Tay, Beng Kang
准确预测新型材料的禁带宽度对于探索其潜在的应用是非常必要的。本文用我们最近提出的GVJ-2 e方法计算了体和单层TMD（MoS_2，MoSe_2，WS_2和WSe_2）的带隙。计算的带隙是在非常好的协议与实验的散装和单层TMD。对于单层MoS_2、MoSe_2、WS_2和WSe_2，直接带隙分别为1.88eV、1.57eV、2.03eV和1.67eV;对于体TMD，间接带隙分别为1.23eV（MoS_2）、1.09eV（MoSe_2）、1.32eV（WS_2）和1.21eV（WSe_2）。GVJ-2 e方法表现出良好的精度，平均绝对误差（MAE）为约0.03 eV的TMD PL间隙（和0.06 eV的QP间隙）。GVJ-2 e方法允许同样准确地获得3D和2D材料的带隙。GVJ-2 e方法的误差明显小于GW（MAE 0.23eV）、杂化泛函HSE（MAE 0.17eV）、TB-mBJ泛函（MAE 0.14eV）等方法的误差。
Accurate prediction of band gap for new emerging materials is highly desirable for the exploration of potential applications. The band gaps of bulk and monolayer TMDs (MoS2, MoSe2, WS2, and WSe2) are calculated with the recently proposed by us GVJ-2e method, which is implemented within DFT framework without adjustable parameters and is based on the total energies only. The calculated band gaps are in very good agreement with experimental ones for both bulk and monolayer TMDs. For monolayer MoS2, MoSe2, WS2, and WSe2, direct band gaps are predicted to be 1.88eV, 1.57eV, 2.03eV, 1.67eV correspondingly, and for bulk TMDs, indirect band gaps of 1.23eV (MoS2), 1.09eV (MoSe2), 1.32eV (WS2), 1.21eV (WSe2) are predicted. The GVJ-2e method demonstrates good accuracy with mean absolute error (MAE) of about 0.03eV for TMDs PL gaps (and 0.06eV for QP gaps). GVJ-2e method allows to equally accurately obtain band gaps for 3D and 2D materials. The errors of GVJ-2e method are significantly smaller than errors of other widely used methods such as GW (MAE 0.23eV), hybrid functional HSE (MAE 0.17eV), TB-mBJ functional (MAE 0.14eV).