Modulating electronic properties in hydrogenated silicon nanotubes†

Abstract

This study employs first-principles calculations to investigate the geometric and electronic properties of hydrogenated silicon nanotubes (SiNTs). SiNTs, particularly in their gear-like configuration, demonstrate unique semiconducting behavior; however, their relatively small intrinsic band gaps limit their applicability in fields requiring moderate band gaps. Significant changes in electronic properties are observed by hydrogenating SiNTs at various levels of adsorption—either full or partial—and different surface configurations (exterior, interior, or dual-sided). These changes include band gap tuning, metal–semiconductor transitions, and enhanced material stability. Generally, complete hydrogen adsorption increases the band gap, while partial hydrogen adsorption can induce metallic or half-metallic characteristics. The study also highlights the significance of spatial charge density redistribution in determining the electronic behavior of SiNTs under hydrogen doping, underscoring their potential for use in electronics, sensors, and energy storage applications.