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

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 cm² V^-1 s^-1 and on/off current ratio of 5 × 10² . Furthermore, µ_FE increases to 1.93 cm² V^-1 s^-1 and operating voltage significantly reduces from 60 to 5 V by using a high permittivity ZrO₂ dielectric layer replacing traditional SiO₂ . 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.