Group research interests

Actively tailorable thermal emission

Hybridization of thermally excited surface plasmon and phonon polaritons, in graphene at different doping levels on a silicon carbide substrate, respectively (see [2]).

Active modulation of the magnitude, directionality, and spatial and temporal characteristics of thermal emission is key for any application that involves contactless thermal management. We study ways to dynamically control thermal emission using emerging materials and device concepts.

Electrical conductance is tunable by more than ten orders of magnitude within a material system. This tunability allows excellent control of the flow of electric currents and is the cornerstone of modern optoelectronics. Analogously, actively tailoring the flow of heat is of critical importance in all applications that require thermal regulation and efficient dissipation of heat, as well as energy harvesting and thermal circuitry. We are interested in controlling heat via radiation, by tailoring the temporal and spatial characteristics of the thermal emission spectrum.

We leverage the unique properties of emerging materials with actively tunable optical response to achieve dynamic modulation of radiative heat transfer and thermal emission in the far-field and near-field regimes. To achieve this, we investigate temperature-dependent phase-change materials, magneto-optical materials, electrostatically tunable material, as well as the mechanical tunability of low-dimensional materials, their heterostructures and heterointerfaces. Furthermore, semiconductors in light-emitting diodes emit photons with a non-zero chemical potential depending on the external bias, which can make hot objects appear colder and vice versa. These functionalities could yield dynamic changes in the infrared signature of materials with applications ranging from thermal camouflage to tunable thermal sources.

Reference:
[1] G. T. Papadakis, C. Ciccarino, L. Fan, P. Narang & S. Fan, “Deep subwavelength thermal switch via resonant mode coupling in monolayer hexagonal boron nitride” arxiv:2011.01184 (2020)
[2] G. T. Papadakis, B. Zhao, S. Buddhiraju, & S. Fan, “Gate-tunable near-field heat transfer” ACS Photonics 6, 709 (2019)
[3] J. Brouillet, G. T. Papadakis & H. A. Atwater, “Experimental demonstration of tunable graphene-polaritonic hyperbolic metamaterial” Optics Express 27, 30225 (2019)