Transactions on Electrical and Electronic Materials

The Korean Institute of Electrical and Electronic Material Engineers (한국전기전자재료학회)
권호 표지
DOI QR코드

DOI QR Code

Transport Properties of Conversion Materials for Digital Radiography

  • Published : 2007.12.31
Download PDF
⟨ Previous Next ⟩

Abstract

Applying the moving photo-carrier grating(MPG) technique and time-of-flight(TOF) measurements, we studied the transport properties of stabilized amorphous selenium typical of the material used in direct conversion X-ray imaging devices. For MPG measurement, we obtained electron and hole mobility and the recombination lifetime of $\alpha-Se$ films with arsenic(As) additions. We found an apparent increase in hole drift mobility and recombination lifetime, especially when 0.3 % As was added into $\alpha-Se$ film, whereas electron mobility decreased with the addition of As due to the defect density. For TOF measurement, a laser beam with pulse duration of 5 ns and wavelength of 350 nm was illuminated on the surface of $\alpha-Se$ with a thickness of 400 ${\mu}m$. The measured hole and electron transit times were about 8.73 ${\mu}s$ and 229.17 ${\mu}s$, respectively.

Keywords

References

  1. J. A. Rowlands and D. M. Hunter, 'X-ray imaging using amorphous selenium: A photoinduced discharge (PID) readout for the digital general radiography', Med. Phys., Vol. 22, p. 1983, 1995
  2. W. Zhao and J. A. Rowlands, 'X-ray image using amorphous selenium: Feasibility of a flat panel selfscanned detector for the digital radiography', Med. Phys., Vol. 22, p. 1595, 1995
  3. T. Akita and S. Yamada, 'Development and evaluation of large-area-selenium based flat panel detector for real-time radiography and fluoroscopy', proc. SPIE, Vol. 3649, p. 14, 1999
  4. C. Haugen, S. O. Kasap, and J. A. Rowlands, 'Charge transport and electron-hole-pair creation energy in stabilized a-Se x-ray photoconductors', J. Phys. D: Appl. Phys., Vol. 32, p. 200, 1999
  5. B. Fogal, R. E. Johanson, G. Belev, S. O'Leary, and S. O. Kasap, J. Non-Cryst. Solids, Vol. 299-302, p. 993, 2002
  6. S. Chand, D: 'Effect of combinational doping on x-ray sensitivity of a-Se films', J. Phys. D: Appl. Phys., Vol. 31, p. 1049, 1998
  7. G. S. Belev, B. Fogal, K. V. Koughia, R. E. Johanson, and S. O. Kasap, 'Dependence of charge -carrier range in stabilized a -Se preparation conditions and alloying', J. Material. Science: Material in Electronics, Vol. 14, p. 841, 2003 https://doi.org/10.1023/A:1026150514758
  8. S. O. Kasap and V. Aiyah, 'X-ray induced hole trapping in electroradiographic plates', J. Appl. Phys., Vol. 69, No. 10, p. 7087, 1991
  9. W. Zhao, G. DeCrescenzo, and J. A. Rowlands, 'Investigation of lag and ghosting in amorphous selenium flat-panel x-ray detector', proc. SPIE, Vol. 4682, p. 9, 2002
  10. U. Haken, M. Haudhausen, and L. Ley, 'Analysis of the moving-photocarrier-grating technique for the determination of mobility and lifetime of photocarriers in semiconductors', Phys. Rev., Vol. 51, No. 16, p. 10579, 1995
  11. J. A. Schmidt, M. Hundhausen, and L. Ley, 'Transport properties of $a-Si_{1-x}C_{x}:H$ films investigated by the moving photocarrier grating technique', Phys. Rev. B, Vol. 62, No. 19, p. 13010, 2000
  12. J. A. Schmidt, M. Hundhausen, and L. Ley, 'Transport properties of amorphous hydrogenerated silicon-carbon alloys', J. Non-Cryst. Sol., Vol. 266, p. 694, 2000
  13. J. A. Schmidt, M. Hundhausen, and L. Ley, 'Analysis of the moving photocarrier-grating technique for the semiconductors of the high defect density', Phys. Rev. B, Vol. 64, p. 104201, 2001
  14. C. H. Park, K. S. Lee, J. B. Kim, and, J. H. Kim, 'The moving photocarrier grating (MPG) technique for the transport properties of a-Se:As films', Trans. EEM, Vol. 6, No. 6, p. 280, 2005
  15. S. O. Kasap, In Handbook of Imaging Materials (A. S. Diamond, ed.), Marcel Dekker, New York, p. 329, 1991
  16. C. Witt, U. Haken, and M. Hundhausen, 'Determination of the photocarrier lifetime in amorphous silicon with the moving photocarrier grating technique', Jpn. J. Appl. Phys., Vol. 33, No. 10A, p. L1386, 1994