Photochromism describes the phenomenon where solid materials change their luminescent color or intensity as a result of exposure to light. Photochromism is generally related to reversible chemical and physical changes upon light irradiation. For example, diarylethenes can rapidly switch between closed and open forms upon exposure to UV and visible light. Bernard L. Feringa and co-workers reported a series of dissymmetric chiral diarylethene derivatives that could switch between open forms of (M)-1o, (M)-2o and closed forms (S,S)-1c, (S,S)-2c (Figure ). The (M)-1o and (M)-2o have intrinsic axial chirality, while the (S,S)-1c, (S,S)-2c have central chirality. The microstructures fabricated by those molecules featured colour-tunability, erasability, reversibility, and multistability. Furthermore, the molecular conformation and intermolecular packing in aggregates can change upon excitation without bond formation, leading to diverse luminescent behaviors. For instance, 1,2-diphenylethane (s-DPE) was reported to be capable of performing light-driven solid-state molecular motion to form excitedstate through-space complexes (ESTSC) (Figure ). The radiative decay of ESTSC could generate an unexpected visible emission due to the clusteroluminescence. Meanwhile, the original packing structure could be recovered from ESTSC after the removal of light irradiation.