Charge doping effect on sliding ferroelectricity by first-principles calculations

Sliding ferroelectric materials present a promising avenue for achieving out-of-plane ferroelectricity in two-dimensional systems, yet further research is imperative to elucidate their intricate microscopic mechanisms. Here, we investigated the charge doping effect on sliding ferroelectricity by first-principles calculations. We found that the ferroelectric polarization and conductivity can coexist at low doping concentrations. The ferroelectric polarization decreases with increasing doping concentration when introducing electrons/holes into the bilayer sliding ferroelectricity with semiconducting character. The rate of decrease is determined by the occupancy ratio of each layer in the conduction and valence bands.