α-MoO3 exhibits promising potential in the field of infrared detection and thermoelectricity owing to its exceptional characteristics of ultra-low-loss phonon polaritons (PhPs). It is of utmost importance to comprehend the phonon interaction exhibited by MoO3 in order to facilitate the advancement of phonon-centric devices. In order to effectively utilize a specific material for device applications, it is imperative to conduct a meticulous examination of its charge transport, thermal conductivity, vibronic, and optical properties [1,2]. The interaction between an electronic continuum and a discrete phonon, commonly referred to as Fano resonance, exerts a profound influence on the aforementioned properties. Here we propose the concept of "Fano resonance" and its significance in regulating the interaction between light and matter by using temperature-dependent Raman spectroscopy [3]. In this work, our key aim of the semi-quantitative analysis is to explain the Raman line shape asymmetry of two scissors modes, as a function of the laser excitation wavelengths and temperature in α-MoO3. A universal generalized theoretical Fano Raman line shape function determines the coupling strength between these two states in α-MoO3.These investigations will facilitate the comprehension of carrier dynamics, thereby enabling the advancement of optoelectronic devices in terms of enhanced speed and response time.

References:
[1] Yang, J., Tang, J., Ghasemian, M. B., Mayyas, M., Yu, Q. V., Li, L. H., & Kalantar-Zadeh, K. High-Q Phonon-polaritons in spatially confined freestanding α-MoO3. ACS Photonics, 2022, 9(3), 905-913.
[2] Tong, Z.; Dumitrica, T.; Frauenheim, T. Ultralow Thermal Conductivity in Two-Dimensional MoO3. Nano Letters 2021, 10 (2021), 4351-4356.
[3] Fano, U. Effects of Configuration Interaction on Intensities and Phase Shifts. Physical Review 1961, 124, 1866−1878.