AVS 50th International Symposium
    Semiconductors Wednesday Sessions
       Session SC+EM-WeP

Paper SC+EM-WeP8
The Dependence of Charge Collection Efficiency on Metal Electrode in Polycrystalline CdZnTe(x=0.04) Material

Wednesday, November 5, 2003, 11:00 am, Room Hall A-C

Session: Poster Session
Presenter: S.Y. Ahn, Korea University
Authors: S.Y. Ahn, Korea University
K.H. Kim, Korea University
S.Y. An, Korea Institute of Science and Technology
J.K. Hong, Korea University
K.N. Oh, Korea University
S.U. Kim, Korea University
Correspondent: Click to Email
There is currently a growing interests on digital X-ray imagers. A direct methods that has several benefits over the indirect methods like convenient image acquistion, storage and transmission, digital image processing, computer-assisted diagosis, real time images, a better spatial resolution dose for equivalent images.@footnote 1@ To generate appropriate e-h pair in CdZnTe film on incident X-ray, thick CdZnTe film was required. Using thermal evaporation method that is generally adquate to deposit thick films, CdZnTe thick films was obtained having ~100 µm in thickness. We investigate the contact between CdZnTe thick film and a variety of metals with the aim of determining whether the choice of metal can improve the performance of X-ray imager detectors, in particular minimizing the dark current. The sample consist of 100 µm thick CdZnTe(x=0.04) with top electrodes formed from Au, In.@footnote 2@ The detection capability of the material has been demonstrated by time-of-flight(TOF) measurements performed on a device made by an n-CdZnTe epilayer. The analysis of the TOF collected charge as a function of the applied voltage give µ @tau@ ~ 10 @super -4@ cm@super 2@/V for this material.@footnote 3@ And we measured resistivity using four-point probe method. CdZnTe(x=0.04) thick film's resistivity is 3 x 10 @super 9@ @ohm@ cm. Au deposited sample is founded to have better properties than others in many respects such as low leakage current, chemicalstability. @FootnoteText@ @footnote 1@ Y. Eisen, A. Shor, J. Crystal Groeth 184/185 (1998) 1302.@footnote 2@ M. J. Mescher, J. F. Hoburg, T. E. Schlesinger, R. B. James IEEE Transactions on Nuclear Science, Vol. 46, NO. 6, December. (1999)@footnote 3@ X. J. Bao, T. E. Schlesinger, R. B. James, Semiconductors for room temperature nuclear detector applications, in: T.E. Schlesinger, R.B. James (Eds.), Semicounductors and Semimetals, Vol. 43, Academic Press, San Diego. (1995).