Strain Engineering on Electronic Properties, Carrier Mobility and Quantum Capacitance of Si ₉ C ₁₅ Siligraphene as Supercapacitor Electrode

ABSTRACT As a warped honeycomb structure, Si 9 C 15 exhibits high stability and mobility, and excellent thermoelectric efficiency. Electronic and optical properties, and quantum capacitance of Si 9 C 15 under biaxial strain are investigated by density functional theory (DFT). Si 9 C 15 exhibits remarkable mechanical stability, with the maximum strain limit of +14% under tensile strain and −16% under compressive strain. Tensile strain keeps the direct character of Si 9 C 15 , while a direct‐to‐indirect transition occurs for Si 9 C 15 under compressive strain. Tensile strain is favorable for faster transfer of electron and hole. Si 9 C 15 under −3% strain has the lowest electron mobility, while Si 9 C 15 under −2% strain has the lowest hole mobility. The systems under tensile strains have better conductivity than those under compressive strains. Si 9 C 15 monolayers under strains are promising cathode materials in whole potential.