Enabling Electrically Controllable Nanophotonic Structures Using 2D Materials*

The rapid development and unique properties of two-dimensional (2D) materials enable them to become intriguing candidates for future photonic applications. We propose new aperiodic multilayer structures based on 2D materials to enable fully electrically controllable switchability. The structure is composed of alternating layers of graphene and hexagonal Boron Nitride (hBN) sandwiched between two layers of Tungsten Disulfide (WS2). This aperiodic multilayer structure provides spectra-altering properties similar to those of more complex and harder to fabricate two- or three-dimensional structures, demonstrating a proof of concept to design and implement more complex structures. We use a hybrid optimization method, consisting of a micro-genetic global optimization algorithm coupled to a local optimization algorithm, to find the optimum thicknesses of the layers in the aperiodic multilayer structure in order to maximize the absorptance to the excellent value of unity at a prespecified wavelength, under zero bias condition. By changing the chemical potential, we can manipulate the refractive index of Graphene and thus have control over absorption. The structure is promising for various applications, such as spacecraft thermal control systems (TCS).