“Temperature-driven modulation of optical and materialistic properties in chemically deposited NbSe2 thin films”

The impact of deposition temperature on the morphological, structural, and optical characteristics of NbSe₂ thin films deposited via chemical bath deposition at room temperature (R.T.), 70 °C, and 100 °C was comprehensively studied. The NbSe₂ thin films exhibited distinct color variations correlated with deposition temperature; alongside compositional purity confirmed through elemental analysis. X-ray diffraction (XRD) revealed crystalline NbSe₂ with lattice parameters a = b = 3.446 Å and c = 12.55 Å, while SEM and TEM analyses demonstrated reduced agglomeration and enhanced dispersion with increasing temperature. FT-IR spectra confirmed characteristic NbSe₂ chalcogenide groups and additional functional groups, while Raman spectroscopy highlighted shifts in the A1g mode, indicating stronger interlayer bonding and enhanced structural integrity at higher temperatures. Optical analysis showed a decrease in direct bandgap energies from 1.23 eV at R.T. to 1.13 eV at 100 °C, with a concurrent reduction in Urbach energy from 0.13 eV to 0.07 eV, signifying improved structural order.

The results highlight the substantial influence of deposition temperature on the crystallinity, shape, and electrical characteristics of NbSe₂ thin films. Elevated temperatures augment structural integrity, diminish defect density, and increase optical properties, so establishing a direct correlation between temperature and material performance. The decrease in bandgap and Urbach energy signifies enhanced charge transfer, making these films suitable for photodetectors, transistors, and energy storage applications. Improved dispersion further facilitates their use in nanoscale electrical and sensing applications, which require stability and homogeneity.