Improved Carrier Separation and Recombination by Ferroelectric Polarization in the CuBiP 2 Se 6 /C 2 N Heterostructure: A Nonadiabatic Molecular Dynamics Study.

The rapid recombination of photogenerated carriers heavily restricts the photocatalytic efficiency. Here, we propose a new strategy to improve catalytic efficiency based on the ferroelectric van der Waals heterostructure (CuBiP 2 Se 6 /C 2 N). Combining density functional theory and the nonadiabatic molecular dynamics (NAMD) method, we have systematically analyzed the ground-state properties and carrier dynamics images in the CuBiP 2 Se 6 /C 2 N heterostructure. Our calculations showed that the ferroelectric polarization of CuBiP 2 Se 6 provides the internal driving force for the photogenerated carriers separation. NAMD results demonstrate that the excited-state carrier transfer and recombination processes in the CuBiP 2 Se 6 /C 2 N are consistent with a type II mechanism. Meanwhile, constructing the ferroelectric heterostructure can effectively prolong the carrier lifetime, from ∼65.98 to ∼124.54 ps. Moreover, the high quantum efficiency and tunable band edge positions mean that the CuBiP 2 Se 6 /C 2 N heterostructure is an excellent potential candidate material for photocatalytic water splitting.