A high mobility air-stable n-type organic small molecule semiconductor with high UV-visible-to-NIR photoresponse

摘要

An organic semiconductor with high carrier mobility and efficient light absorption over a wide spectral range is of the most important yet challenging material for constructing a broadband responsive organic photodetector.However,the development of such organic semiconductors,especially for air-stable n-type organic small molecule semiconductors,is still at an early stage.Here we report the fabrication of high-performance n-type semiconducting crystalline nanosheets and the development of air-stable field-effect transistors,phototransistors,with high response over a broad spectrum.The n-type small molecule semiconductor is assembled into a crystalline nanosheet based on the solvent-phase interfacial self-assembly method.N-type field-effect transistors with high electron mobility are fabricated and their electrical performances exhibit excellent air stability.Impressively,the demonstrated phototransistors exhibit an ultrahigh responsivity over a wide spectral range from 365 to 940 nm,with a maximum photoresponsivity of 9.2×10^(5) AW-1 and specific detectivity of 5.26×10^(13) Jones,which is the best performance among the reported n-type organic small molecule-based phototransistors.