Interlayer-Decoupled Sc-Based Mxene with High Carrier Mobility and Strong Light-Harvesting Ability

Two-dimensional (2D)
van der Waals (vdW) layered materials offer
a unique combination of electronic and structural properties attractive
for technological applications. Most of them show strong vdW interactions,
which lead to interlayer-coupled optoelectronic properties due to
quantum confinement. Here we present a systematic computational study
of one Mxene, 2D double-metal-layered scandium chloride carbides (Sc2CCl2). Unlike conventional quantum-confined nanosystems,
2D Sc2CCl2 exhibits weak vdW interactions with
robust interlayer-decoupled optoelectronic properties and extremely
high and anisotropic carrier mobilities of about 1–4.5 ×
104 cm2 V–1 s–1 that consequently produce comparatively large drain currents. Specifically,
the 2D Sc2CCl2 family has strong light-harvesting
ability and could be utilized as efficient donor materials in excitonic
solar cells. Overall, in combination with high structural stability
against ambient conditions, interlayer-decoupled robust optoelectronic
properties potentially relax the requirements for the fabrication
of high-quality monolayers and for selection of suitable substrates
and suggest promising next-generation optoelectronic applications.