Efficient thermal management of electronic devices by constructing interlayer phonon bridges
Gaojie Han, Hongli Cheng, Yuezhan Feng, Shiliang Zhang, Jingwen Dong, Bing Zhou, Xianhu Liu, Chuntai Liu, Guangming Tao, Changyu Shen
Abstract
Layered film-based thermal management materials with high in-plane thermal conductivity can effectively diffuse point heat sources and prevent local overheating. However, their low through-plane thermal conductivity limits its overall heat dissipation. Here, we introduce a honeycomb-gel densification strategy that forms zigzag yet continuous interlayer phonon bridges within the layered structure. This design establishes bi-directional thermal pathways, boosting both in-plane and through-plane thermal conductivity by 488.9% and 503.3% of the aramid nanofiber/boron nitride nanosheet, respectively, compared to random-gel densified films. Also, the aramid nanofiber/boron nitride nanosheet film exhibits high solar reflectivity, infrared emissivity, and thermal radiation, enabling efficient subambient cooling (17.2 °C at 100 mW/cm²) for heat-generating devices. The overall heat dissipation of layered films is limited by the low through-plane thermal conductivity. Here, the authors enhance thermal conductivity by constructing bi-directional thermal pathways through a zigzag yet continuous interlayer phonon bridge.