β-Ga₂O₃ nanowires-based humidity sensors prepared on GaN/sapphire substrate

We report the growth of β-Ga₂O₃ nanowires (NWs) on GaN substrate and the fabrication of β-Ga₂O₃ NW humidity sensors. It was found that average length and diameter were ∼ 10 μm and 100 nm, respectively. It was also found that the current of the NWs increased as we increased the relative humidity because of the n-type nature of β-Ga₂O₃. Through measuring current-voltage characteristics of the fabricated device at 25°C, it was found that the measured currents were 5.99 × 10^-5, 6.42 × 10 ^-5, 6.76 × 10^-5, 7.33 × 10^-5, and 7.93 × 10^-5 A when measured with 35%, 50%, 65%, 85%, and 95%-relative humidity, respectively.