Photochromic Semiconductors with Record-High Dielectric Permittivity Gain at Room Temperature

Bistable-state dielectric properties without maintaining external stimuli after switching are highly desirable for nonvolatile memory devices; however, research on switchable dielectric materials was mostly limited to the stimulation-constant mode. This work reports a record-high dielectric permittivity gain through the bistable-state modulation mode in two photochromic semiconductors (PSCs), and reveals the general structure characteristic and intrinsic physical reasons for the increase of dielectric permittivity. This discovery will guide the design for switchable dielectric materials with dielectric permittivity gain in the future.