FeIn(2)S(4) Nanocrystals: A Ternary Metal Chalcogenide Material for Ambipolar Field‐Effect Transistors

An ambipolar channel layer material is required to realize the potential benefits of ambipolar complementary metal–oxide–semiconductor field‐effect transistors, namely their compact and efficient nature, reduced reverse power dissipation, and possible applicability to highly integrated circuits. Here, a ternary metal chalcogenide nanocrystal material, FeIn(2)S(4), is introduced as a solution‐processable ambipolar channel material for field‐effect transistors (FETs). The highest occupied molecular orbital and the lowest unoccupied molecular orbital of the FeIn(2)S(4) nanocrystals are determined to be −5.2 and −3.75 eV, respectively, based upon cyclic voltammetry, X‐ray photoelectron spectroscopy, and diffraction reflectance spectroscopy analyses. An ambipolar FeIn(2)S(4) FET is successfully fabricated with Au electrodes (E (F) = −5.1 eV), showing both electron mobility (14.96 cm(2) V(−1) s(−1)) and hole mobility (9.15 cm(2) V(−1) s(−1)) in a single channel layer, with an on/off current ratio of 10(5). This suggests that FeIn(2)S(4) nanocrystals may be a promising alternative semiconducting material for next‐generation integrated circuit development.