Effects of humidity on the electrical characteristics of ZnO nanowire devices

Abstract

Changes in the electrical characteristics of individual ZnO nanowire (NW) devices when they are exposed to wet air (80% relative humidity, RH) at room temperature are investigated. Significant roughening on the surface of ZnO NWs is observed after they are exposed to wet air for more than tens of hours. I-V characteristics taken after exposure to humidity show positive shifts of the threshold voltages in ZnO NW field effect transistors (FETs), which indicate depletion of carriers. These results have implication about the long-term stability of such devices when they need to be in direct contact with the ambient environment for their operations.Surface roughening on a ZnO NW due to exposure to humidity (left) and corresponding changes in transfer characteristics of the device with its exposure time to humidity (right).

Tuning ZnO Nanowire Dissolution by Electron Beam Modification of Surface Wetting Properties

“…Despite the wide range of applications, chemical stability and solubility of these nanostructures can have a strong impact on biological purposes as well as electronic devices reliability. Even though ZnO nanostructures are generally considered chemically stable, degradation and corrosion of ZnO was observed in atmospheric conditions under prolonged exposure to environmental moisture or high relative humidity, after interaction with water and after hydrothermal treatments. − In particular, it was observed that ZnO corrosion strongly depends on humidity, CO 2 concentration, and substrates . Indeed, ZnO can interact with water and form zinc hydroxide, and subsequently this hydrated layer can react with CO 2 to form zinc carbonates on the surface that can strongly affect the electrical and optical properties of ZnO NWs .…”

Effects of humidity on performance of electric-double-layer oxide-based thin-film transistors gated by nanogranular SiO2 solid electrolyte

“…Those factors make the threshold voltage to drift toward positive direction. 22 It indicates that reducing the relate humidity makes the operation mode of the devices changing from enhance mode to depletion mode. Moreover, protons need a longer time to move from the gate electrode-electrolyte interface to the electrolyte-semiconductor interface with the lower humidity due to the low speed, which results in changes in field-effect mobility and subthreshold swing.…”