Future Mott transistor with high current density using hydrogen-terminated diamond

In order to develop future transistors that reduce heat generation during high-speed switching [1], the Mott insulator-to-metal transition (IMT) provides an explanation for the high drain-source current density (I_DS ≈ 1.3 A/mm, [2]) measured in field-effect transistors based on hydrogen-terminated diamond. A local metallic phase, satisfying the Mott criterion, is induced by an IMT in a p-type semiconductor. Hole (p-type) conductivity is enabled by the coupling between hydrogen and carbon on the diamond surface and by charge transfer doping due to surface termination with a high electron affinity material. The local Mott metal phase on the surface of the p-type semiconductor leads to high carrier and current densities. Transistors utilizing this effect can be classified as Mott power transistors. A channel material consisting of local Mott metal regions on the surface of a p-type semiconductor, such as hydrogen-terminated diamond, may be considered an inhomogeneous, topological Mott insulator. [1] Appl. Phys. Lett. 123, 262102 (2023). [2] Jpn. J. Appl. Phys. 51,090112 (2012).