Hostname: page-component-586b7cd67f-t8hqh Total loading time: 0 Render date: 2024-11-23T11:53:01.229Z Has data issue: false hasContentIssue false

A Study of Bismuth Induced Levels in CZT Using TEES/TSC

Published online by Cambridge University Press:  31 January 2011

Raji Soundararajan
Affiliation:
[email protected], Washington State University, Center for Materials Research, Pullman, Washington, United States
Kelly A. Jones
Affiliation:
[email protected], Washington State University, Center for Materials Research, Pullman, Washington, United States
Santosh Swain
Affiliation:
[email protected], Washington State University, Center for Materials Research, Pullman, Washington, United States
Kelvin Lynn
Affiliation:
[email protected], Washington State University, Center for Materials Research, Pullman, Washington, United States
Get access

Abstract

Considering the desirable effects of doping CdTe with heavy elements like Bi, we have grown a Cadmium Zinc Telluride (Zn=10%) ingot with Bi (doping levels ∼1014 to 1015 at/cm3) as the heavy element dopant for use as a room temperature radiation detector, using the Bridgman method. In-spite of a high bulk resitivity (∼1010?cm), and the ability to hold high electric field (>2000 V/cm), these lightly doped crystals had a poor spectral resolution for the Co-57 photo peaks and ??e measurements were so low that these measurement were not reliable. Thermo electric effect spectroscopy (TEES) and thermally stimulated current (TSC) experiments on samples C and F (single crystals close to the tip and the heel of the ingot respectively) have revealed various defect levels in the band gap. Among these defect levels, we have identified and characterized two Bi-related deep levels namely a deep donor level L5 (thermal ionization energy: 0.33[5] to 0.39[5] eV and trap cross-section: 7.1[5] × 10-17 to 2.54 [5] × 10-16 cm2), and a deep acceptor level L8 (thermal ionization energy of 0.82 [5] eV and trap cross-section of 2.59 [5] × 10-12 cm2). These levels were responsible for the observed high electrical resistivity (∼1010 ?*cm) in the CdZnTe samples. From a comparison to studies on Bi doped CdTe samples, level L8 was tentatively associated with the (0/-) transition of (BiCd- - OTe) complex, however is still under study. Since these defect levels also act as trapping centers for charge carriers, in spite of the semi-insulating behavior the samples are poor radiation detectors.

Type
Research Article
Copyright
Copyright © Materials Research Society 2009

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Selez, Cs., Shan, Y.Y. Lynn, K.G. Moodenbough, A.R. and Eissler, E.E. Phys. Rev. B 53, 6495 (1997).Google Scholar
2. Emanuelson, P. Omling, P. Meyer, B.K. Wienecke, M. and Schenk, M. Phys. Rev. B 47, 15578 (1993).Google Scholar
3. Krsmanovic, N. Lynn, K.G. Weber, M.H. Tjossem, R. Gessmann, Th. Phy. Rev. B 62, (24) 16279 (2000).Google Scholar
4. Soundararajan, R. Lynn, K.G. Awadallah, S. C, Szeles, Wei, Su-Huai, J. Elect. Mat. 35, (6) 1333 (2006).Google Scholar
5. Wei, Su-Huai, and Zhang, S.B. Phy. Stat. Sol. B 229 (1), (2002).Google Scholar
6. Funaki, Minoru, Ando, Yukio, Jinnai, Ryuji, Tachibana, Akira, and Ohno, Ryoichi, http://www.acrorad.co.jp/pdf/Development_of_CdTe_detectors.pdfGoogle Scholar
7. Terterian, S. Chu, M. Ting, D. Wu, L.C. Wang, C.C. Szawlowski, M. Vissor, G. and Luke, P.N. J. Elec. Mat. 32, p796 (2003).Google Scholar
8. Saucedo, E. Fornaro, L. Sochinskii, N.V. Cuna, A. Corregidor, V. Granados, D. Dieguez, E. IEEE Trans. Nuc. Sci 51, (6) (2004).Google Scholar
9. Saucedo, E. Martinez, O. Ruiz, C.M. Vigil-Galan, O., Benito, I. Fornaro, L. Sochinskii, N.V. Dieguez, E. J. Cry. Gro. 291, 416 (2006).Google Scholar
10. Suh, Jong Hee, Cho, Sin Hang, Won, Jae Ho, Hong, Jin Ki, Kim, Sun Ung, J. Kor. Phy. Soc. 49 (2006).Google Scholar
11. Bliss, M. Gerlach, D.C. Cliff, J.B. Toloczko, M.B. Barnett, D.S. Ciampi, G. Jones, K.A. Lynn, K.G. Nuc. Inst. Met. Phy. Res. A 579 (2007).Google Scholar
12.O. Vigil-Galan, Brown, M. Ruiz, C.M. Vidal-Borbolla, M.A., Ramirez-Bon, R., Sanchez-Meza, E., Tufino-Velazquez, M., Calixto, M. Estela, Compaan, A.D. Contreras-Puente, G., Thin Sold Films 516 (2008).Google Scholar
13. Babentsov, V. Franc, J. Hoschl, P. Fiederle, M. Benz, K.W. Sochinskii, N.V. Dieguez, E. and James, R.B. Cryst. Res. Technol., 1–5 (2009)Google Scholar
14. Du, Mao-HuaBismuth-induced deep levels and carrier compensation in CdTePhy. Rev. B 78, (1995).Google Scholar
15. Saucedo, E. Franc, J. Elhadidy, H. Horodysky, P. Ruiz, C.M. Bermudez, V. and Sochinskii, N.V. J. Appl. Phy. 103, (2008).Google Scholar
16. Bube, R. H.Photoconductivity in Solids”, p. 242 (New York: Wiley, 1960).Google Scholar