The correlation between electronic disorder (quantified by the Urbach energy $E_U$) and phonon linewidth $\left(\mathrm{\Gamma }\right)$ is known to be linear. However, both parameters exhibit temperature dependence, raising the question of whether the slope of the $\mathrm{\Gamma }$ vs $E_U$ plot remains constant with temperature. In this study, we investigate temperature dependence of the slope, denoted as $\xi$, which represents the sensitivity of phonon mode to changes in disorder. By applying theoretical models for the temperature dependence of $\mathrm{\Gamma }$ and $E_U$, we derive an expression for $\xi \left(T\right)$, revealing its nonlinear behavior at varying temperatures. Our analysis, based on Raman and optical absorption spectra of ${\mathrm{EuFeO}}_3$, demonstrates the explicit temperature dependence of $\xi$. This provides insights into the disorder sensitivity of vibrational modes, which is crucial for understanding phonon dynamics and transport properties. The findings are further supported by additional investigations on ${\mathrm{TiO}}_2$, emphasizing the utility of combined optical and Raman spectroscopic techniques in probing phonon-resolved disorder sensitivity in materials with finite bandgap where $E_U$ can be observed.

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• Lattice dynamics
• Semiconductors
• Optical spectroscopy
• Raman spectroscopy