Self-powered photovoltaic liquid crystal light modulators (SP-PSLM)

Photo-voltaic light modulators consist of a liquid crystal layer integrated with an organic photovoltaic structure. Addressing them with light produces an internal voltage that changes the liquid crystal orientation and the optical transmission properties of the device. They offer an exciting prospect for autonomous, light controlled smart displays and visors. Herein we report the development of self-activated light modulators, whose transmittance drops with increasing light intensity without applying an external power supply. This could be achieved by introducing a tandem photovoltaic structure that allows to produce larger voltages. Crossed polarized intensity measurements on devices based on different liquid crystals and photovoltaic layers are presented to clarify the physical mechanisms underlying self-activation.