Transactions on Electrical and Electronic Materials

The Korean Institute of Electrical and Electronic Material Engineers (한국전기전자재료학회)
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X-ray Sensitivity of Hybrid-type Sensor based on CaWO4-Selenium for Digital X-ray Imager

  • Park, Ji-Koon (Department of Biomedical Engineering, College of Biomedical Science and Engineering, Inje University) ;
  • Park, Jang-Yong (Department of Biomedical Engineering, College of Biomedical Science and Engineering, Inje University) ;
  • Kang, Sang-Sik (Department of Biomedical Engineering, College of Biomedical Science and Engineering, Inje University) ;
  • Lee, Dong-Gil (Department of Biomedical Engineering, College of Biomedical Science and Engineering, Inje University) ;
  • Kim, Jae-Hyung (Medical Imaging Research Center, Inje University) ;
  • Nam, Sang-Hee (Medical Imaging Research Center, Inje University)
  • Published : 2004.08.01
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Abstract

The development of digital x-ray detector has been extensively progressed for the application of various medical modalities. In this study, we introduce a new hybrid-type x-ray detector to improve problems of a conventional direct or indirect digital x-ray image technology, which composed of multi-layer structure using a CaWO$_4$ phosphor and amorphous selenium (a-Se) photoconductor. The leakage current of our detector was found to be ∼180 pA/cm$^2$ at 10 V/m, which was significantly reduced than that of a single a-Se detector. The x-ray sensitivity was measured as the value of 4230 pC/cm$^2$/mR at 10 V/m. We found that the parylene thin film between a CaWO$_4$ phosphor and an a-Se layer acts as an insulator to prevent charge injection from indium thin oxide (ITO) electrode into an a-Se layer under applied bias.

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References

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