Coupled Optical Response of Armchair Graphene Nanoribbons and Single Wall Carbon Nanotube Hybrid Structures

Nanostructured hybrid materials with tailored properties are essential for advancing emerging technologies in optoelectronics and semiconductor applications. Through a combination of broad-spectrum Fourier transform spectroscopy (0.1–2.5 eV) and theoretical calculations, the characteristic optical bandgap of the hybrids composed by ultra-narrow armchair graphene nanoribbons (AGNRs) encapsulated within single-walled carbon nanotubes (SWCNTs) is revealed. These hybrid structures are synthesized using a terrylene precursor followed by high-temperature treatments. The findings demonstrate that ribbon-host interactions significantly affect the optical response of the system, resulting in both a reduction and slight shift of the Eii excitations of the SWCNTs. Consistent across both experimental measurements and calculations, a bandgap below 0.1 eV is observed for the hybrid structure. Additionally, multiple vibrational peaks are identified in the mid-infrared spectrum attributable specifically to the encapsulated AGNRs, clearly distinguishable from any signals arising from the non-encapsulated terrylene precursor. This work provides critical insights into the electronic structure and optical properties of these hybrid nanomaterials, paving the way for their potential integration into next-generation optoelectronic devices.