Yttrium Doped Copper (II) Oxide Hole Transport Material as Efficient Thin Film Transistor.

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-CuO thin films are developed through solid state method at 200oC and recognized as high performance p-channel inorganic thin-film transistors (TFTs). In sharp contrast, CuO is formed by oxidative decomposition of copper acetylacetonate yielding 100nm thick and 40.9 Scm-1 conductive compact layer of 2.47 eV band gap and ~1.44 × 1019 cm-3carrier density. Yttrium doping generates denser layer, Cu2Y2O5 phase in the lattice, of wide band gap, 2.63 eV. The electrical conductivity increases nine fold on 2% Y addition to CuO and carrier density becomes 2.97 × 1021 cm-3, the highest reported so far. The TFT devices perform remarkably with high field-effect mobility (µsat) of 3.45 cm2V-1s-1 and 5.3 cm2V-1s-1, and considerably high current-on/off ratio 0.11 × 104 and 9.21 × 104, for CuO and Y-CuO films, respectively at -1V operating voltage. A very small width hysteresis, 0.01 (CuO) and 1.92V (1% Y-CuO) depict good bias stability. Both the devices work in enhancement mode with stable output characteristics for multiple forward sweeps (5 to -60V) at -1Vg.