Temperature-dependent in-plane thermal conductivity of SrTiO3 membranes enhanced by surface phonon polaritons.

Surface phonon polaritons (SPhPs) enable unique surface heat dissipation on nanoscale polarized membranes, countering reduced lattice thermal conductivity (κ) from decreased membrane thickness (d) and increased temperature (T). SrTiO 3 , a polar perovskite material, supports SPhPs across a wide Reststrahlen band linked to its substantial polarizability. However, limited studies explore SPhPs' role in SrTiO 3 heat transfer. Moreover, the d , T , and dielectric mismatch (Δ ɛ) in the upper and lower media sandwiching the membrane can modulate the SPhPs' resonance, affecting the polaritonic in-plane κ. This study thoroughly investigates the correlation between SPhPs and polaritonic κ of SrTiO 3 in symmetric and asymmetric systems. The predicted polaritonic κ of 100-nm-thick suspended SrTiO 3 membrane can reach 18.60 W/mK at 300 K, more than doubling the lattice κ. High ambient dielectric constant, elevated temperature, and reduced thickness redshift the thermal hot spot of SPhPs resonant modes in membrane to a lower frequency, predominantly influencing the polaritonic κ. Our work centers on investigating the significant potential of SPhPs to augment in-plane heat transfer, offering valuable insights into the feasibility of thermal management for microelectronic devices. [ABSTRACT FROM AUTHOR]