High-performance and scalable metal-chalcogenide semiconductors and devices via chalco-gel routes

We report a general strategy for obtaining high-quality, large-area metal-chalcogenide semiconductor films from precursors combining chelated metal salts with chalcoureas or chalcoamides. Using conventional organic solvents, such precursors enable the expeditious formation of chalco-gels, which are easily transformed into the corresponding high-performance metal-chalcogenide thin films with large, uniform areas. Diverse metal chalcogenides and their alloys (MQ x : M = Zn, Cd, In, Sb, Pb; Q = S, Se, Te) are successfully synthesized at relatively low processing temperatures ( 2 Se 3 active layers. The CdSe TFTs exhibit a maximum field-effect mobility greater than 300 cm 2 V −1 s −1 with an on/off current ratio of >10 7 and good operational stability (threshold voltage shift 10 13 Jones and seven-stage ring oscillators operating at a speed of ~2.6 MHz (propagation delay of