Electrical Engineering of Phononic and Photonic Emissions in 2D Heterostructures*

Two-dimensional (2D) heterostructures, owing to their rich electronic, optical, and vibrational properties, unlock great possibilities towards designing ultra-compact optoelectronic, electromechanical, and optomechanical devices. To date, most of the work has focused on the intrinsic phononic and photonic properties of 2D heterostructures and utilized layer engineering to modify their properties. The effective couplings between external electrical means and the inherent optical and vibrational properties are highly desirable due to the rich fundamental physics and practical significance towards electrically operational devices, yet have not been achieved thus far. Through the systematic study of phononic and photonic emissions of 2D semiconductors interfacing with functional electronic materials, we report a sensitive dependence of the phonon modes and optical emissions with externally applied voltages. The crystal fields of 2D semiconductors are shown to be substantially altered by voltages, leading to strong coupling between external electrical means and inherent phononic and photonic emissions. Our work could pave practical avenues towards the further development of atomically thin optoelectronic and electromechanical devices.