Hydrogen-incorporated ZnO nanowire films: stable and high electrical conductivity

Post-growth hydrogen annealing treatment of highly oriented ZnO nanowire (NW) films (ZnO : H) results in high electrical conductivity (3.7 × 103 S m−1) and fully suppressed defect emission at room temperature. The formation of hydrogen-related vacancy complexes is responsible for the suppression of vacancies ( Vo+ and Vo2+), leading to a reduction in defect-based emission. ZnO : H NW films show five orders larger stable electrical conductance with a four-fold increment in carrier mobility (7–28 cm2 V−1 s−1). As compared with pristine NWs, the carrier concentration in ZnO : H NW films increases from 1015 to 1019 cm−3, which is in the range of commercial transparent conducting oxides. X-ray photoelectron spectroscopy and secondary ion mass spectrometry analyses reveal stable OH bond formation, which strongly supports the prediction of H doping. These films offer a promising conducting oxide platform for photovoltaic applications. (paper)