Chemical structures of light-driven axially chiral molecular switch Azo4 (a) and photoinsensitive chiral dopant R5011 (b). (c) Schematic illustrations of the mechanism of light-driven dynamic handedness inversion in self-organized helical superstructures induced through the doping of Azo4 and R5011 with opposite-handedness. At the initial state, the combined doping of two chiral molecules in an achiral nematic LC host yields an overall left handedness which is dominated by that of (trans, trans)-Azo4. Upon UV irradiation, the left-handed contribution from (trans, trans)-Azo4 decreases significantly due to its trans-cis isomerization, while the R5011 maintains a comparable right-handed contribution with the initial state. When the right handedness becomes dominant, the overall right-handed helical superstructures are achieved.