Enhanced charge transport in 2D inorganic molecular crystals constructed with charge-delocalized molecules

Abstract

Outstanding charge transport in molecular crystals is of great importance in modern electronics and optoelectronics. The widely adopted strategies to enhance charge transport, such as restraining intermolecular vibration, are mostly limited to organic molecules, which are nearly inoperative in 2D inorganic molecular crystals currently. In this contribution, charge transport in 2D inorganic molecular crystals is improved by integrating charge-delocalized Se₈ rings as building blocks, where the delocalized electrons on Se₈ rings lift the intermolecular orbitals overlap, offering efficient charge transfer channels. Besides, α-Se flakes composed of charge-delocalized Se₈ rings possess small exciton binding energy. Benefitting from these, α-Se flake exhibits excellent photodetection performance with an ultrafast response rate (~5 μs) and a high detectivity of 1.08 × 10¹¹ Jones. These findings contribute to a deeper understanding of the charge transport of 2D inorganic molecular crystals composed of electron-delocalized inorganic molecules and pave the way for their potential application in optoelectronics.