Room-temperature spin transport through band-to-band tunneling at semiconductor p-n junctions

Abstract

Oki K., Ueda S., Usami T., et al. Room-temperature spin transport through band-to-band tunneling at semiconductor p-n junctions. Physical Review Applied 23, L051005 (2025); https://doi.org/10.1103/physrevapplied.23.l051005.We report electrical spin injection, transport, and detection at room temperature through band-to-band tunneling (BTBT) at semiconductor p-n junctions. Using germanium-based lateral spin-valve devices with p-n-junction electrodes, we experimentally observe pure spin-current transport through BTBT at room temperature. Asymmetric bias-current dependence of the spin signals is evidently found, which originates from the spin injection via BTBT through p-n junctions or the spin extraction via localized states near p-n junctions. Notably, even for the use of a thin p-type semiconductor layer at the spin injector and detector, we find clear spin-transport properties at room temperature. This study will open a path for the room-temperature operation of a spin-based tunnel field-effect transistor with a p-n junction