On the Working Mechanisms of Molecules-Based Van der Waals Dielectrics |
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Authors: | Pengyu Li Yinghe Zhao Huiqiao Li Tianyou Zhai |
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Affiliation: | State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei, 430074 China |
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Abstract: | Sb2O3 molecules offer unprecedented opportunities for the integration of a van der Waals (vdW) dielectric and a 2D vdW semiconductor. However, the working mechanisms underlying molecules-based vdW dielectrics remain unclear. Here, the working mechanisms of Sb2O3 and two Sb2O3-like molecules (As2O3 and Bi2O3) as dielectrics are systematically investigated by combining first-principles calculations and gate leakage current theories. It is revealed that molecules-based vdW dielectrics have a considerable advantage over conventional dielectric materials: defects hardly affect their insulating properties. This shows that it is unnecessary to synthesize high-quality crystals in practical applications, which has been a long-standing challenge for conventional dielectric materials. Further analysis reveals that a large thermionic-emission current renders Sb2O3 difficult to simultaneously satisfy the requirements of dielectric layers in p-MOS and n-MOS, which hinders its application for complementary metal-oxide-semiconductor (CMOS) devices. Remarkably, it is found that As2O3 can serve as a dielectric for both p-MOS and n-MOS. This work not only lays a theoretical foundation for the application of molecules-based vdW dielectrics, but also offers an unprecedentedly competitive dielectric (i.e., As2O3) for 2D vdW semiconductors-based CMOS devices, thus having profound implications for future semiconductor industry. |
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Keywords: | 2D  van der Waals (vdW)  semiconductors As2O3 MoS2 Sb2O3 van der Waals (vdW)  dielectrics |
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