Researchers at the City University of New York’s Advanced Science Research Center (CUNY ASRC) recently published a groundbreaking study in Nature that showcases a more efficient method for exciting long-wave infrared and terahertz waves, offering new hope for addressing overheating issues in electronic devices. This innovative technology centers around the use of two key materials—graphene and hexagonal boron nitride (hBN)—to effectively excite and control phonon-polaritons, a special type of electromagnetic wave.
Graphene, a single-atom-thick layer of carbon atoms, is renowned for its exceptional electrical conductivity and high electron mobility. In this study, graphene is ingeniously sandwiched between two layers of hexagonal boron nitride, creating a highly ordered heterostructure. Hexagonal boron nitride (hBN) is a hexagonal crystal insulator known for its excellent thermal conductivity and electrical insulating properties. Its crystal structure complements that of graphene, enhancing the overall electron mobility within the system.
The unique combination of these materials lies in the way hexagonal boron nitride encapsulates graphene, protecting it from external environmental disturbances while further increasing the electron mobility within the graphene layer. This high mobility allows electrons to accelerate more rapidly under the influence of an electric current, facilitating efficient interactions with hyperbolic phonon-polaritons (HPhPs) within the hBN. These interactions not only boost the excitation efficiency of phonon-polaritons but also enable these special electromagnetic waves to focus long-wave infrared energy into nanometer-scale regions, thereby achieving highly efficient thermal management.
Experimental results demonstrated that applying an electric field of just 1 V/µm was sufficient to significantly excite the electroluminescence of HPhPs. This finding overcomes the previous limitations that relied on expensive mid-infrared or terahertz lasers for excitation, making the practical application of phonon-polaritons more cost-effective and efficient. This technological advancement not only enhances the potential applications of phonon-polaritons in thermal management and infrared technologies but also lays a solid foundation for the development of next-generation molecular sensors.
The synergistic effect of graphene and hexagonal boron nitride in this research underscores the pivotal role that advanced materials play in solving modern electronic devices’ thermal management challenges. As this technology continues to be optimized and disseminated, future electronic devices are expected to become more compact, efficient, and energy-saving, driving the advancement of energy-efficient and compact technologies and redefining the performance and application scope of modern electronic devices.
Stanford Advanced Materials (SAM) provides graphene and hexagonal boron nitride (hBN).
