Geometric, Electronic, and Transport Predictions on Two-Dimensional Semiconducting Silicon with Kagome Lattice: Implications for Nanoscale Field-Effect Transistor Applications

Two-dimensional (2D) semiconducting silicon (Si) is significant for the development of micro/nanoelectronics because of their compatibility with the current Si-based technology and the advantages common to 2D electronic materials. Here, by focusing on the kagome lattice (KL), we design a set of semiconducting 2D KL-Si for nanoscale field-effect transistor (FET) applications. First-principles calculations demonstrate that both stable geometric properties and tunable semiconducting electronic properties can be obtained for the 2D KL-Si with different thicknesses. The 2D KL-Si features electronic band gaps ranging from 2.82 to 1.36 eV as a function of increasing the layer thickness and hole/electron mobility as large as about 10 3 cm 2 ·V –1 ·s –1 . By applying the KL-Si to nanoscale FETs, we obtain giant negative differential resistances with peak-valley ratios over 10 7 and excellent switching performance fulfilling the requirements of the International Technology Roadmap for Semiconductors. Our study demonstrates the importance of kagome topology in the design of 2D Si crystals with excellent semiconducting properties as well as their promising application in nanoelectronic devices.