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Nuclear Instruments and Methods in Physics Research A 665 (2011) 15–18

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Nuclear Instruments and Methods in
Physics Research A journal homepage: www.elsevier.com/locate/nima

Fabrication and characterization of a ZnO X-ray sensor using a high-resistivity ZnO single crystal grown by the hydrothermal method
Haruyuki Endo a,n, Tetsuya Chiba a, Kazuyuki Meguro a, Kyo Takahashi a, Mitsuru Fujisawa a,
Shigeaki Sugimura b, Shinya Narita c, Yasube Kashiwaba a,d, Eiichi Sato e a Electronic information technology department, Iwate Industrial Research Institute, 3-35-2, Iiokashinden, Morioka Iwate 020-0852, Japan
New Materials Department, Tokyo Denpa Co. Ltd., 5-6-11 Chuo, Ohta-ku, Tokyo, 143-0024, Japan c Faculty of Engineering, Department of Electrical Engineering, Electronics and Computer Science, Iwate University, 3-18-8 Ueda, Morioka, Iwate 020-8550, Japan d Iwate University, 3-18-8 Ueda, Morioka, Iwate 020-8550, Japan e Department of Physics, Iwate Medical University, 2-1-1 Nishitokuta, Yahaba Iwate 028-3694, Japan b article info

abstract

Article history:
Received 21 December 2010
Received in revised form
20 October 2011
Accepted 4 November 2011
Available online 20 November 2011

We investigated the X-ray detection capability of a fabricated Pt/ZnO diode using a high-resistivity ZnO single crystal grown by the hydrothermal method. The X-ray sensor consists of a Pt electrode on the Zn-face, an Au/
Ti electrode on the O-face and a (0 0 0 1) ZnO substrate with high resistivity. The fabricated X-ray sensor showed ohmic-like characteristics in the measurement of current-applied voltage characteristics. We attributed these ohmic characteristics to degradation of the surface quality of the ZnO substrate caused by handling damage that occurred when carrying out a series of electrical and optical ZnO characterizations.
The fabricated X-ray sensor at a bias of 20 V responded to X-rays