Highly Efficient Silicon Photonic Microheater Based on Black Arsenic-Phosphorus

While black phosphorus has shown excellent optoelectronic properties in many aspects, the environmental instability ultimately places limits on its practical applications. Black arsenic-phosphorus (b-AsP), an alloy of black phosphorus with arsenic atoms, has emerged as a new 2D material with better stability. Recently, the heterostructure via integration of 2D material with nanophotonic waveguides is opening an avenue for many on-chip applications of phosphorene. However, the thermo-optic (TO) properties, which are widely used for waveguide heaters, are not studied on b-AsP yet. Herein, the TO effects of a b-AsP/silicon van der Waals heterostructure are first investigated and its application as a transparent waveguide heater is demonstrated. A high efficiency of 0.74 nm mW(-1) is achieved with a nonresonant and broadband heater based on 20 nm thick b-AsP, which eliminates the need for enhancement by cavity-assisted light-matter interaction, and thus allows for compact footprint, broadband operation, and low latency.