Charge Transfer and Interface Engineering of the Pentacene and MoS2 Monolayer Complex

Molecular doping of monolayer MoS2 provides a great opportunity to modulate its electronic properties for the potential applications in high performance devices. Density functional theory computations are performed to investigate the charge transfer and electrostatic potential modulation upon the adsorption of pentacene molecule on the surface of MoS2 monolayer (ML). Theoretical calculations indicate that interfacial charge transfer is negligible between pentacene and 2H-MoS2 ML while significant in the pentacene/1T-MoS2 ML complex, which is attributed to the match of energy levels near the Fermi level in the latter case. Moreover, molecular doping of pentacene induces substantial structure changes of the substrate resulting in large adsorption energy, which helps stabilize the 1T-MoS2 ML. Depending on different substrate phases and doping configurations, the interfacial dipole barrier and related work function of MoS2 ML may be modulated in a wide range of the order of about 1 eV. The findings therefore shed light on the possibility of developing the desired organic/inorganic complex for electrical and optoelectronic devices by molecular doping via charge transfer modulation and interface engineering.