Simultaneous Optical Tuning of Hole and Electron Transport in Ambipolar WSe2 Interfaced with a Bicomponent Photochromic Layer: From High-Mobility Transistors to Flexible Multilevel Memories

The interfacing of 2D materials (2DMs) with photochromic molecules provides an efficient solution to reversibly modulate their outstanding electronic properties and offers a versatile platform for the development of multifunctional field-effect transistors (FETs). Herein, optically switchable multilevel high-mobility FETs based on few-layer ambipolar WSe2 are realized by applying on its surface a suitably designed bicomponent diarylethene (DAE) blend, in which both hole and electron transport can be simultaneously modulated for over 20 cycles. The high output current modulation efficiency (97% for holes and 52% for electrons) ensures 128 distinct current levels, corresponding to a data storage capacity of 7 bit. The device is also implemented on a flexible and transparent poly(ethylene terephthalate) substrate, rendering 2DM/DAE hybrid structures promising candidates for flexible multilevel nonvolatile memories.