THERMAL TRANSPORT AND PHONONICS IN NANOSCALE SYSTEMS: MECHANISMS, MATERIALS, AND APPLICATIONS

Abstract

Understanding and manipulating heat transfer at the nanoscale is central to advancing modern technology in nanoelectronics, thermoelectrics, energy conversion, and phononics. Unlike bulk systems where Fourier’s law of heat conduction prevails, thermal transport at nanometer dimensions is dominated by wave–particle duality of phonons, enhanced boundary effects, and ballistic transport phenomena. This article reviews the fundamental mechanisms of thermal transport in nanoscale systems, focusing on phonon dynamics, scattering processes, and confinement effects in low-dimensional materials and engineered nanostructures. We critically analyze the role of phononic crystals, nanowires, nanotubes, and two-dimensional materials and highlight experimental and theoretical methodologies. Applications in thermal management, thermoelectrics, and phononic devices are discussed. Challenges in modeling multi-scale phonon transport and future directions for thermal control technologies are outlined.