Four strategies towards customized rainbow/white light emission from a series of organic charge-transfer cocrystals and their heterostructures

Abstract

A series of structurally isomorphic charge-transfer cocrystals with 1,2,4,5-tetracyanobenzene as the electron acceptor is presented in this contribution to highlight four strategies towards tunable rainbow/white light emission in crystals, i.e., tailoring the energy levels for an adjustable rainbow light emission from violet to red by changing different electron donors, regulating the packing mode for a fine-tuning of the luminescence by switching crystallization pathways for different polymorphs, modulating charge-transfer solid solution by mixing different donors for white light emission via spectrum superposition, and constructing heterostructures through heteroepitaxial seeded growth from multicolored luminescent crystals. These four approaches at different levels, from molecular composition, supramolecular packing, solid solution, to block-heterogeneity between different crystals, may provide a systematic scheme to guide the future creation of customized multifunctional light-emitting systems.