Anisotropic magnetotransport in few-layer Nb-doped WSe₂

Hole-doped epitaxial WSe₂ films with thicknesses of three to six monolayers were grown by a hybrid pulsed-laser deposition, in which metallic alloy targets were laser-ablated under a controlled Se vapor. The Hall effect indicated active Nb-dopant concentrations of 10-50 at%. Scanning transmission electron microscopy revealed that Nb atoms occupy W sites, and 2H- as well as 3R-stacking coexist in the films. A striking anisotropy between magnetoconductance (MC) for in-plane (B // I) and out-of-plane (B ⊥ I) magnetic fields was found, showing a complete absence of weak antilocalization for B ⊥ I, while it restores for B // I at intermediate temperatures. The band structure of 2H-3R Nb:WSe₂ obtained by first-principles calculations is shown, based on which a few possible origins of the MC will be discussed.