Programme

P.28 -- Posters, VCTP-50

Date: Tuesday, 5 August 2025

Time: 08:30 - 10:00

The Debye−Callaway model for thermal conductivity calculation of black phosphorus nanoribbons

Nguyen Viet Chien

Phenikaa University, Hanoi, Vietnam

Thermal conductivity (κ) in solids consists of contributions from both electronic thermal conductivity (κₑ) and lattice thermal conductivity (κₗ), with the latter often significantly reduced in low-dimensional materials. Understanding phonon transport in these systems requires reliable modeling of κₗ. The Debye-Callaway model, derived from the phonon Boltzmann transport equation, provides a robust theoretical framework by incorporating key phonon scattering mechanisms. In this study, we apply the Debye-Callaway model to analyze the lattice thermal conductivity of black phosphorus (BP) nanoribbons synthesized via chemical vapor transport (CVT) at different growth rates (7, 0.3, and 0.05 K/min). Experimental κₗ data, obtained using a suspended microdevice, show a significant increase in the 50–200 K range as the growth rate decreases, suggesting enhanced phonon transport. Fitting the experimental data to the Debye-Callaway model, while accounting for boundary, point defect, Normal, and Umklapp scattering, indicates that this enhancement arises primarily from the suppression of phonon–point defect scattering, consistent with improved crystalline quality at lower growth rates. Our results confirm the Debye-Callaway model’s effectiveness in linking phonon scattering to microstructural quality, providing key insights into thermal transport in BP nanoribbons and related nanomaterials.

Presenter: Nguyen Viet Chien