Large difference of doping behavior of tetracyanoquinodimethane (TCNQ) and 2,3,5,6-Tetrafluoro-7,7,8,8- tetracyanoquinodimethane (F4-TCNQ) on field effect transistor with channel of atomic layer MoS2
Large difference of doping behavior of tetracyanoquinodimethane (TCNQ) and 2,3,5,6-Tetrafluoro-7,7,8,8- tetracyanoquinodimethane (F4-TCNQ) on field effect transistor with channel of atomic layer MoS2
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DOI：
10.1016/j.apsusc.2021.151252
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发表时间：
2022-01
影响因子：
6.7
通讯作者：
Hiroki Waizumi;Muhammad Shamim Al Mamun;T. Takaoka;Md Iftekharul Alam;Yudai Tanaka;A. Ando;Zhipeng Wang;R. Arafune;T. Komeda
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作者：
Hiroki Waizumi;Muhammad Shamim Al Mamun;T. Takaoka;Md Iftekharul Alam;Yudai Tanaka;A. Ando;Zhipeng Wang;R. Arafune;T. Komeda
研究了四氰基对苯二酚二甲烷（TCNQ）和2，3，5，6-四氟-7，7，8，8-四氰基对苯二酚二甲烷（F4-TCNQ）两种分子的掺杂对由原子级薄的MoS 2沟道组成的场效应晶体管（FET）性能的影响差异的机理。通过观察漏极电流-栅极电压曲线的阈值电压漂移（ΔVth）来检测两种分子的电子受体行为。TCNQ仅显示出104 V的轻微位移，但F4-TCNQ分子显示出1033 V的大值。在紫外光电子能谱（UPS）中检测到与少量F4-TCNQ沉积类似的快速变化作为费米能级位移。DFT计算结果表明，优化后的两种分子均为平躺构型，电荷转移到基底的差异不足以解释ΔVth的差异。相反，我们想提出一个模型，其中F4-TCNQ分子的F原子在S-缺陷处的键合有助于ΔVth的初始快速变化。
We examined the mechanism of the large difference of the doping effect of two molecules of tetracyanoquinodimethane(TCNQ) and 2,3,5,6-Tetrafluoro-7,7,8,8- tetracyanoquinodimethane (F4-TCNQ) on the field effect transistor (FET) property, which is composed of the atomically thin MoS2channel. The electron-acceptor behaviors of the two molecules are detected by examining the threshold voltage shift (ΔVth) of the drain current vs gate voltage curve plot. It shows only a mild shift of ∼4 V for the TCNQ but it shows a large value of ∼33 V for the F4-TCNQ molecule. The similar rapid change with small amount of F4-TCNQ deposition was detected as the Fermi level shift in the ultra violet photoemission spectroscopy (UPS). The DFT calculation shows the flat lying configuration for both molecules after the structural optimization, and the difference of the charge transfer to the substrate is not large enough to explain the difference of theΔVth. Instead, we want to propose a model in which the bonding of the F atom of the F4-TCNQ molecule at the S-defect contribute to the initial rapid variation of theΔVth.