Mbe growth of ge-based diluted magnetic semiconductors

As the continuous scaling of complementary metal–oxide–semiconductor (CMOS) technology approaches its limit, spintronics has received tremendous attention as it could promise next‐generation devices with non‐volatile and low variability. In particular, diluted magnetic semiconductors with unique electric‐field‐controlled ferromagnetism could have high potential for building magnetoelectric devices with ultralow power dissipation. However, device realization has been hindered for a decade due to the low Curie temperature (T _c) and easy formation of intermetallic compounds. To address such critical challenges, we present a systematic investigation on enhancing the T _c through configuring nanostructures in Mn‐doped Ge, including quantum dots (QDs), nanodisks and nanomeshes. It can be well demonstrated that the size confinement can significantly suppress the formation of intermetallic compounds, and thus more Mn could be introduced into the substitutional position, increasing the T _c. Meanwhile, the electric‐field control of ferromagnetism and magnetoresistance was successfully demonstrated. Our results may provide a paradigm for fundamentally understanding the high T _c in the diluted magnetic semiconductor nanostructure and realizing ultralow power‐dissipation spintronics devices.