Raman spectroscopy and carrier scattering in 2D tungsten disulfides with vanadium doping

Abstract

Doped 2D transition metal dichalcogenides have attracted much attention as room-temperature ferromagnetism can be realized in such semiconductors. For example, the magnetism of vanadium-doped WS₂ (V-WS₂) has been revealed, but there is still confusion about how the substituted vanadium atoms affect the carrier scattering of V-WS₂. Here, we study the electron–phonon coupling and carrier scattering of V-WS₂ by temperature-dependent Raman spectroscopy and electrical transport measurements. We identify a characteristic Raman peak at ∼212 cm⁻¹, a fingerprint for V-WS₂. We also reveal that the electron–phonon coupling is strengthened in V-WS₂ and becomes more sensitive to temperature, which suppresses the carrier mobility and improves the sensitivity of its electronic performance to temperature. Moreover, the substituted vanadium not only causes an n- to p-type transition of the carrier transport behavior but also serves as charged impurities, making ionization scattering dominate the carrier transport process in V-WS₂. Such modulation of carrier transport behavior in V-WS₂ will facilitate its application in electronic and spintronic devices.