Large Spin-To-Charge Conversion at the Two-Dimensional Interface of Transition-Metal Dichalcogenides and Permalloy

Spin-to-charge conversion is an essential requirement
for the implementation
of spintronic devices. Recently, monolayers (MLs) of semiconducting
transition-metal dichalcogenides (TMDs) have attracted considerable
interest for spin-to-charge conversion due to their high spin–orbit
coupling and lack of inversion symmetry in their crystal structure.
However, reports of direct measurement of spin-to-charge conversion
at TMD-based interfaces are very much limited. Here, we report on
the room-temperature observation of a large spin-to-charge conversion
arising from the interface of Ni80Fe20 (Py)
and four distinct large-area (∼5 × 2 mm2) ML
TMDs, namely, MoS2, MoSe2, WS2, and
WSe2. We show that both spin mixing conductance and the
Rashba efficiency parameter (λIREE) scale with the
spin–orbit coupling strength of the ML TMD layers. The λIREE parameter is found to range between −0.54 and −0.76
nm for the four ML TMDs, demonstrating a large spin-to-charge conversion.
Our findings reveal that the TMD/ferromagnet interface can be used
for efficient generation and detection of spin current, opening new
opportunities for novel spintronic devices.