Fig. 2: Surface potentials of vacuum-deposited films.
From: Spontaneous orientation polarization driven by designing molecular asymmetry

a Directions of the permanent dipole moments of 6F-2PI, FL-2PI, 6H-2PI, CH-2PI, and SO-2PI. The red arrows represent the directions of permanent dipole moments. b Thickness dependence of the surface potentials of 6F-2PI, FL-2PI, 6H-2PI, CH-2PI, and SO-2PI films.