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
Abstract

In this study, the electronic and optical properties of germanium carbide nanotubes (GeCNTs) with different chiral indices under applied strain were investigated using first-principles calculations based on density functional theory (DFT) within the PBE-GGA approximation. The results show that the (5,0) GeCNT exhibits a near-zero direct band gap with quasi-metallic behavior, whereas the (10,0) nanotube is a direct-band-gap semiconductor with a band gap of 1.29 eV. Optical analyses reveal that the main absorption and reflectivity features in out-of-plane polarization occur within the energy range of 1.5–4.0 eV, and their responses are significantly influenced by chirality and applied strain. These findings demonstrate that the tunable electronic and optical properties of GeCNTs make them promising candidates for optical sensors, nanoscale photonic devices, and infrared detection technologies.

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Subjects

Volume 5, Issue 2
Summer 2026

  • Receive Date 29 May 2026
  • Revise Date 08 July 2026
  • Accept Date 13 July 2026