Electronic Properties and Modulation Effects on Edge-Modified GeS₂ Nanoribbons

Abstract

GeS₂ monolayer has been successfully prepared. Here, to further expand their applications and discover new physical property, we construct armchair-type GeS₂ nanoribbons (AGeS₂NR) and use different concentrations of H and O atoms for the edge modification, as well as their structural stability, electronic properties, carrier mobility, and physical field modulation effects are studied deeply. The results show that the edge-modified nanoribbons have a higher energy and thermal stability. The bare edge nanoribbons are nonmagnetic semiconductors, while the edge modification can change the bandgap of AGeS₂NR and make them become wide or narrowed bandgap semiconductor, or a metal, which is closely related to the elimination or partial elimination of the edge states or the creation of hybridization bands. Thus edge modification extends the application range of nanoribbons in the field of electronic devices and optical devices. In addition, the carrier mobility is found to be very sensitive to the edge modification, the carrier mobility (electrons and holes) of nanoribbons can be tuned to have a difference up to one order of magnitude, and the carrier mobility polarization up to one order of magnitude occurs. Strain effect studies reveal that the semiconducting nanoribbons are robust in keeping the electronic phase unchanged over a wide strain range, which is useful for maintaining the stability of the electron transport in the related devices. Most of the semiconducting nanoribbons have the stability to keep the semiconducting properties unchanged under high external electric field, but the bandgap can be reduced significantly with the increase of the electric field. In short, this study provides a theoretical analysis and reference for understanding the property of GeS₂ nanoribbons and developing related devices.