Yttrium Doped Copper (II) Oxide Hole Transport Material as Efficient Thin Film Transistor
Sadia Baig, Pankaj Kumar, Jenner H. L. Ngai, Yuning Li, Safeer Ahmed
Abstract
Abstract This work reports development of yttrium doped copper oxide (Y−CuO) as a new hole transport material with supplemented optoelectronic character. The pure and Y‐doped CuO thin films are developed through a solid‐state method at 200 °C and recognized as high performance p‐channel inorganic thin‐film transistors (TFTs). CuO is formed by oxidative decomposition of copper acetylacetonate, yielding 100 nm thick and conductive (40.9 S cm −1 ) compact films with a band gap of 2.47 eV and charge carrier density of ∼1.44×10 19 cm −3 . Yttrium doping generates denser films, Cu 2 Y 2 O 5 phase in the lattice, with a wide band gap of 2.63 eV. The electrical conductivity increases nine‐fold on 2 % Y addition to CuO, and the carrier density increases to 2.97×10 21 cm −3 , the highest reported so far. The TFT devices perform remarkably with high field‐effect mobility (μ sat ) of 3.45 cm 2 V −1 s −1 and 5.3 cm 2 V −1 s −1 , and considerably high current‐on/off ratios of 0.11×10 4 and 9.21×10 4 , for CuO and Y−CuO films, respectively (at −1 V operating voltage). A very small width hysteresis, 0.01 V for CuO and 1.92 V for 1 % Y−CuO, depict good bias stability. Both the devices work in enhancement mode with stable output characteristics for multiple forward sweeps (5 to −60 V) at −1V g .