Low-frequency noise characteristics of epitaxial ZnO photoconductive sensors

We report the fabrication of epitaxial ZnO photoconductive sensors on sapphire substrates. With an incident light wavelength of 370 nm and a 5 V applied bias, we achieved a sensor responsivity of 20.5 mA/W. It was also found that low-frequency and high-frequency noises in the fabricated sensors were dominated by 1/f type and shot noises, respectively. With a 5 V applied bias, it was found that noise equivalent power and normalized detectivity of the fabricated sensors were 1.83 x 10(-6) W and 6.91 x 10(5) cm Hz(0.5) W-1, respectively. (C) 2007 The Electrochemical Society.