Engineering Optically Switchable Transistors with Improved Performance by Controlling Interactions of Diarylethenes in Polymer Matrices

Abstract

The integration of photochromic molecules into semiconducting polymer matrices via blending has recently attracted a great deal of attention, as it provides the means to reversibly modulate the output signal of electronic devices by using light as a remote control. However, the structural and electronic interactions between photochromic molecules and semiconducting polymers is far from being fully understood. Here we perform a comparative investigation by combining two photochromic diarylethene moieties possessing similar energy levels yet different propensity to ag-gregate with five prototypical polymer semiconductors exhibiting different energy levels and structural order, rang-ing from amorphous to semicrystalline. Our in-depth photochemical, structural, morphological and electrical charac-terization reveals that the photoresponsive behavior of thin-film transistors (TFTs) including polymer/diarylethenes blends as the active layer is governed by a complex interplay between the relative position of the energy levels and the polymer matrix microstructure. By matching the energy levels and optimizing the molecular packing, high-performance optically switchable organic thin-film transistors were fabricated. These findings represent a major step forward in the fabrication of light-responsive organic devices.