Increasing the Efficiency of a Spintronic THz Emitter Based on WSe2/FeCo

Abstract

We report an increase in terahertz (THz) radiation efficiency due to FeCo/WSe₂ structures in the reflection geometry. This can be attributed to an absorption increase in the alloy FeCo layer at the input FeCo/WSe₂ interface due to constructive interference, as well as to the backward transport of hot carriers from FeCo to WSe₂. In contrast to the transmission geometry, the THz generation efficiency in the reflection is much less dependent on the magnetic layer thickness. Our results suggest a cheap and efficient way to improve the characteristics of THz spintronic emitters with the conservation of a full set of their important properties.