Suppression of extra carriers for enhanced intrinsic piezoelectric properties of ultrathin MoS2 through various metal dopants

We study the piezoelectric behavior of metal-doped monolayer MoS2. Its three-dimensional charge density, work function (WF), and piezoresponse with various metal dopants are theoretically predicted based on density functional theory, and the real-time piezoelectric power of these samples is experimentally verified. Selected p-type metal dopants (Au, Ag, Pd, Pt, and Al) increase the WF of monolayer MoS2, affecting electron emission from the MoS2 surface. The reason is that p-type metal dopants suppress excess electrons and prevent screening effects. A nanogenerator constructed from Au-doped monolayer MoS2 has been used to explore the possibility of a practical device.