Tailoring Surface Morphology for Characteristic Exciton–Plasmon Resonances in Self-Assembled CuS Nanostructured Films

• Published in: Journal of physical chemistry. C Vol. 127; no. 24; pp. 11623 - 11631
• Main Authors: Singh, Harkawal, Arora, Isha, Natarajan, Vanasundaram, Kumar, Sandeep, Sharma, Praveen Kumar
• Format: Journal Article
• Language: English
• Published: American Chemical Society 22.06.2023
• Subjects: C: Spectroscopy and Dynamics of Nano, Hybrid, and Low-Dimensional Materials
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/acs.jpcc.3c02156

Nanoscale surface corrugation strongly influences the propagation of plasmons and its induced characteristics in self-organized periodic nanostructures. Here, the role of varying surface roughness and thickness in periodic nanostructures of a self-assembled CuS system has been reported. The mixing of surfactants is used to translate the contrary type of clustering processes in a bottom-up fabrication method. X-ray diffraction (XRD) study identifies the improved crystallinity and quantization effects for invariable hexagonal crystal structures. The elaboration of Raman measurements has distinguished the formulated interlayer soft phonon modes from interlayer electron–phonon interactions that gave split-off features in surface enhanced Raman scatterings (SERS). The absorption spectra in linear and diffuse reflectance geometry monitor the scattering of the exciton–plasmon field in terms of defect states, Urbach’s energy, and optical gap. The true nature of periodic energy exchange between exciton–plasmon coupled systems has been derived from the Drude–Lorentz oscillator model fitting to near-normal incidence reflectance spectra. The effects on a dimensionally constrained plasmon’s momentum space and phase velocities are visible in the extraordinary optical behavior of the derived refractive index and dielectric constants. The correlative study on electronic, oxidation, and valence states has been reported using X-ray photoelectron spectroscopy (XPS) measurements. This approach of fabrication and characterization is expected to overcome the major roadblocks for the formation of metamaterials with identical large arrays for photonic devices.