Room-Temperature Fabricated Thin-Film Transistors Based on Compounds with Lanthanum and Main Family Element Boron.

For the first time, compounds with lanthanum from the main family element Boron (LaBx ) were investigated as an active layer for thin-film transistors (TFTs). Detailed studies showed that the room-temperature fabricated LaBx thin film was in the crystalline state with a relatively narrow optical band gap of 2.28 eV. The atom ration of La/B was related to the working pressure during the sputtering process and the atom ration of La/B increased with the increase of the working pressure, which will result in the freer electrons in the LaBx thin film. LaBx -TFT without any intentionally annealing steps exhibited a saturation mobility of 0.44 cm²·V−1 ·s−1 , which is a subthreshold swing ( SS ) of 0.26 V/decade and a Ion / Ioff ratio larger than 10⁴. The room-temperature process is attractive for its compatibility with almost all kinds of flexible substrates and the LaBx semiconductor may be a new choice for the channel materials in TFTs.