Angstrom-Size Defect Creation and Ionic Transport through Pores in Single-Layer MoS2
Angstrom-Size Defect Creation and Ionic Transport through Pores in Single-Layer MoS2
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DOI：
10.1021/acs.nanolett.7b04526
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发表时间：
2018-03-01
期刊：
影响因子：
10.8
通讯作者：
Drndic, Marija
中科院分区：
文献类型：
--
作者：
Thiruraman, Jothi Priyanka;Fujisawa, Kazunori;Drndic, Marija
薄膜中的原子缺陷工程为离子和分子过滤和分析提供了机会。虽然分子动力学(MD)计算已经被用来模拟原子空位的电导，但缺乏相应的实验。我们通过Ga+离子辐照在悬浮的单层二硫化钼(MoS_2)中产生亚纳米空位，得到了平均孔径和最大直径分别接近0.5和1 nm的膜，其孔径约为300~1200个孔。像差校正扫描电子显微镜(AC-STEM)显示，空位中有缺失的Mo和S原子。在拉曼光谱和光致发光光谱中分别观察到了纵向声带和与缺陷相关的光致发光。随着辐照剂量的增加，平均空位面积基本保持不变，而空位(气孔)的数量增加。离子电流与电压的关系是非线性的，电导与直径为1 nm的MoS_2单孔的电导相当，证明了分布中较小的孔的电导可以忽略不计。一以贯之，MD模拟显示具有直径的毛孔
Atomic-defect engineering in thin membranes provides opportunities for ionic and molecular filtration and analysis. While molecular-dynamics (MD) calculations have been used to model conductance through atomic vacancies, corresponding experiments are lacking. We create sub-nanometer vacancies in suspended single-layer molybdenum disulfide (MoS2) via Ga+ ion irradiation, producing membranes containing similar to 300 to 1200 pores with average and maximum diameters of similar to 0.5 and similar to 1 nm, respectively. Vacancies exhibit missing Mo and S atoms, as shown by aberration-corrected scanning transmission electron microscopy (AC-STEM). The longitudinal acoustic band and defect-related photoluminescence were observed in Raman and photoluminescence spectroscopy, respectively. As the irradiation dose is increased, the median vacancy area remains roughly constant, while the number of vacancies (pores) increases. Ionic current versus voltage is nonlinear and conductance is comparable to that of 1 nm diameter single MoS2 pores, proving that the smaller pores in the distribution display negligible conductance. Consistently, MD simulations show that pores with diameters