Room‐Temperature Solution‐Synthesized p‐Type Copper(I) Iodide Semiconductors for Transparent Thin‐Film Transistors and Complementary Electronics

Abstract Here, room‐temperature solution‐processed inorganic p‐type copper iodide (CuI) thin‐film transistors (TFTs) are reported for the first time. The spin‐coated 5 nm thick CuI film has average hole mobility ( µ FE ) of 0.44 cm 2 V −1 s −1 and on/off current ratio of 5 × 10 2 . Furthermore, µ FE increases to 1.93 cm 2 V −1 s −1 and operating voltage significantly reduces from 60 to 5 V by using a high permittivity ZrO 2 dielectric layer replacing traditional SiO 2 . Transparent complementary inverters composed of p‐type CuI and n‐type indium gallium zinc oxide TFTs are demonstrated with clear inverting characteristics and voltage gain over 4. These outcomes provide effective approaches for solution‐processed inorganic p‐type semiconductor inks and related electronics.