Xing's research work can be loosely categorized into 4 areas, supported by DoD, NSF, SRC, DoE, etc.

III-V Nitride materials and devices. Example projects include AlN/GaN ultrascaled high electron/hole mobility transistors for high-speed high-power applications, fundamental science of polarization doping in polar semiconductors, applications of polar semiconductors in electronics and in photonics including UV optoelectronics, non-linear optical materials, piezoelectric properties and RF filters, GaN power diodes and transistors, resonant tunneling diodes, negative differential resistance and plasma based THz sources, wafer fused enabled hybrid structures, and BN.
Oxide materials and devices. Example projects include epitaxy, physics and applications of Ga2O3, Al2O3 and related materials, high-performing electronics based on complex oxide semiconductors.
Low-dimensional materials and quantum materials. Ongoing projects include epitaxy and properties of hBN, epitaxial superconductors integrated on the III-V nitrides platform and related science and technologies. Past projects include nanowires and devices (InGaN and II-VIs), 2D crystal materials and devices including van der Waals epitaxy, carrier electrostatics and transport, optoelectronic responses, p-n junctions and heterostructures, field modulation and tunneling, metamaterials and THz applications, graphene physics and devices.
Logic and memory materials and devices. Ongoing projects include conceptualizing and developing non-volatile memories with high endurance for processing-in-memory (PIM) such as spin-orbit-torque field-effect transistor (SOTFET) and ion-based memories. Past projects include steep slope transistors for high-efficiency logic and RF electronics, especially tunnel FETs. We pioneered design, fabrication and characterization of III-V TFETs, later 2D-crystal based steep slope transistors: the Thin-TFETs.