Electronic properties and modulation effects on edge-modified GeS<sub>2</sub> nanoribbons

GeS₂ monolayers have been successfully prepared in this work. To further expand their applications and discover new physical properties, we construct armchair-type GeS₂ nanoribbons (AGeS₂NR) and use different concentrations of H and O atoms for the edge modificationand their structural stabilities, electronic properties, carrier mobilities, and physical field modulation effects are studied in depth. The results show that the edge-modified nanoribbon has a higher energy and thermal stability. The bare edge nanoribbon is a nonmagnetic semiconductor, while the edge modification can change the bandgap of AGeS₂NR and make it a 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 fields of electronic devices and optical devices. In addition, the carrier mobility is found to be very sensitive to the edge modification: the carriers’ (electrons’ and holes’) mobilities of nanoribbons can be adjusted to a difference of up to one order of magnitude, and the difference in carrier mobility polarization can be tuned to one order of magnitude. 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 device. 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.