A bistable viologen‐TiO2 color switch

Abstract— The electro‐optical characteristics of a pixel configuration used in electrochromic viologen‐TiO₂ passive‐matrix devices are studied. The configuration has two stable color states in an intermediate voltage regime. Color switching is performed by applying voltages outside this regime. The bistability is due to electrolyte‐additive controlled electron trapping in the color‐changing viologen molecules.