Systematic control of spontaneous orientation polarization via polar molecular blending

Polar organic semiconducting molecules can exhibit a preferential alignment of their permanent dipole moments, inducing a giant surface potential via spontaneous orientation polarization (SOP). Previous work has shown how blends of polar and non-polar molecules offer one approach to either engineer SOP and its deleterious effect on OLED efficiency. Here, the emphasis is instead on composite films where both components exhibit SOP. In these systems, the observed SOP follows a linear combination of neat film behaviors. This study expands the avenues for control over SOP via molecular blending that can be further exploited for applications.