Multielement 2D layered material photodetectors

The pronounced quantum confinement effects, outstanding mechanical strength, strong light-matter interactions and reasonably high electric transport properties under atomically thin limit have conjointly established 2D layered materials (2DLMs) as compelling building blocks towards the next generation optoelectronic devices. By virtue of the diverse compositions and crystal structures which bring about abundant physical properties, multielement 2DLMs (ME2DLMs) have become a bran-new research focus of tremendous scientific enthusiasm. Herein, for the first time, this review provides a comprehensive overview on the latest evolution of ME2DLM photodetectors. The crystal structures, synthesis, and physical properties of various experimentally realized ME2DLMs as well as the development in metal-semiconductor-metal photodetectors are comprehensively summarized by dividing them into narrow-bandgap ME2DLMs (including Bi2O2X (X = S, Se, Te), EuMTe3 (M = Bi, Sb), Nb2XTe4 (X = Si, Ge), Ta2NiX5 (X = S, Se), M2PdX6 (M = Ta, Nb; X = S, Se), PbSnS2), moderate-bandgap ME2DLMs (including CuIn7Se11, CuTaS3, GaGeTe, TlMX2 (M = Ga, In; X = S, Se)), wide-bandgap ME2DLMs (including BiOX (X = F, Cl, Br, I), MPX3 (M = Fe, Ni, Mn, Cd, Zn; X = S, Se), ABP(2)X(6) (A = Cu, Ag; B = In, Bi; X = S, Se), Ga2In4S9), as well as topological ME2DLMs (MIrTe4 (M = Ta, Nb)). In the last section, the ongoing challenges standing in the way of further development are underscored and the potential strategies settling them are proposed, which is aimed at navigating the future advancement of this fascinating domain.