Electronic and Optical Analysis of Strained Germanium Carbide Nanotubes Using a Density Functional Theory Approach

Document Type : Original Article

Author

Department of Electrical Engineering, South Tehran Branch, Islamic Aazd University, Tehran, Iran

Abstract
Introduction:The development of advanced functional nanomaterials is crucial for next-generation optoelectronic devices. Germanium Carbide Nanotubes (GeCNTs) have emerged as promising candidates due to their unique electronic properties and potential for structural tunability, making them highly relevant for high-tech applications.
Methods:In this study, the electronic and optical properties of GeCNTs with various chiral indices were investigated under the influence of hydrostatic strain. The calculations were performed using first-principles methods based on Density Functional Theory (DFT) within the Perdew-Burke-Ernzerhof Generalized Gradient Approximation (PBE-GGA) framework.
Findings:The results demonstrate a significant dependence of electronic behavior on the nanotube chirality. Specifically, the (5,0) GeCNT exhibits a near-zero direct bandgap, behaving as a quasi-metallic structure, whereas the (10,0) GeCNT functions as a semiconductor with a direct bandgap of 1.29 eV. Optical property analysis in out-of-plane polarization reveals that the most significant optical transitions occur within the 1.5 to 4 eV energy range. Furthermore, both changes in chirality and the application of hydrostatic strain lead to substantial modifications in the optical response of these nanostructures.
Conclusion:GeCNTs offer exceptional tunability in both electronic and optical domains. These characteristics position GeCNTs as highly suitable materials for applications in optical sensors, photonic devices, and infrared detectors, particularly within the aerospace and defense sectors.

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Subjects

Volume 5, Issue 2
Summer 2026
Pages 50-62

  • Receive Date 28 February 2026
  • Revise Date 07 May 2026
  • Accept Date 29 May 2026