Abstract
The transient and steady-state dark current behaviors in various amorphous selenium (a-Se) detectors are analyzed by developing mathematical models considering all possible mechanisms (e.g., carrier depletion, thermal generation, and carrier injection from electrodes) and charge carrier transport properties of a-Se. The theoretical models are validated by comparing them with recently published measured transient and steady-state dark currents in various a-Se detectors. The fittings of the models with the experimental results reveal various important material and device properties such as the optimum trap depth and concentrations in the blocking layers for faster stabilization and lower dark current, and the effective barrier height between the metal/a-Se contacts. The thermal generation current is significantly higher in avalanche detectors (at extremely high fields) than that in conventional detectors. The effective blocking layers for both holes and electrons are necessary for the minimum level of the dark current. The minimum dark current is determined by the thermal generation current. The thermal generation current can be lowered by reducing the mid gap defect states.
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S.O. Kasap, J.B. Frey, G. Belev, O. Tousignant, H. Mani, J. Greenspan, L. Laperriere, O. Bubon, A. Reznik, G. DeCrescenzo, K.S. Karim, J.A. Rowlands, Sensors 11, 5112 (2011)
I. Saito, W. Miyazaki, M. Onishi, Y. Kudo, T. Masuzawa, T. Yamada, A. Koh, D. Chua, K. Soga, M. Overend, M. Aono, G.A.J. Amaratunga, K. Okano, Appl. Phys. Lett. 98, 152102 (2011)
A. Reznik, W. Zhao, Y. Ohkawa, K. Tanioka, J.A. Rowlands, J. Mater. Sci. Mater. Electron. 20, S63 (2009)
S.A. Mahmood, M.Z. Kabir, O. Tousignant, J. Greenspan, IEEE Trans. Nucl. Sci. 59, 597 (2012)
S.O. Kasap, J.A. Rowlands, J. Mater. Sci. Mater. Electron. 11, 179 (2000)
V.I. Mikla, V.V. Mikla, J. Mater. Sci. Mater. Electron. 20, 1095 (2009)
G.S. Belev, B. Fogal, K.V. Koughia, R.E. Johanson, S.O. Kasap, J. Mater. Sci. Mater. Electron. 14, 841 (2003)
M.Z. Kabir, S.O. Kasap, J.A. Rowlands, in Photoconductors for X-ray Image Detectors, eds. by Kasap, Capper. Springer Handbook of Electronic and Photonic Materials, chap. 48 (Springer, 2006)
S.O. Kasap, J.B. Frey, G. Belev, O. Tousignant, H. Mani, L. Laperriere, A. Reznik, J.A. Rowlands, Phys. Status. Solidi. B 246, 1794 (2009)
S.O. Kasap, J.A. Rowlands, IET Circuits Devices Syst. 149, 85 (2002)
J.B. Frey, G. Belev, O. Tousignant, H. Mani, L. Laperriere, S.O. Kasap, J. Appl. Phys. 112, 014502 (2012)
M.Z. Kabir, S.O. Kasap, J. Vac. Sci. Technol. A 20, 1082 (2002)
X. Zhu, H. Sun, D. Yang, J. Yang, X. Li, X. Gao, J. Mater. Sci. Mater. Electron. 25, 3337 (2014)
K. Jandieri, O. Rubel, S.D. Baranovskii, A. Reznik, J.A. Rowlands, S.O. Kasap, J. Mater. Sci. Mater. Electron. 20, S221 (2009)
K. Kikuchi, Y. Ohkawa, K. Miyakawa, T. Matsubara, K. Tanioka, M. Kubota, N. Egami, Phys. Status. Solidi. C 8, 2800 (2011)
M. Brinza, J. Willekens, M.L. Benkhedir, E.V. Emelianova, G.J. Adriaenssens, J. Mater. Sci. Mater. Electron. 16, 703 (2005)
S.O. Kasap, B. Polischuk, D. Dodds, Rev. Sci. Instrum. 61, 2080 (1990)
S.A. Mahmood, M.Z. Kabir, O. Tousignant, H. Mani, J. Greenspan, P. Botka, Appl. Phys. Lett. 92, 223506 (2008)
M. Abkowitz, Phil. Mag. Lett. 58, 53 (1988)
S.A. Mahmood, M.Z. Kabir, Curr. Appl. Phys. 9, 1393 (2009)
G.A. Marlor, Phys. Rev. 159, 540 (1967)
Z. He, Nucl. Instrum. Methods A 463, 250 (2001)
K.C. Kao, W. Hwang, Electrical Transport in Solids (Pergamon, England, 1981), p. 333
R.A. Street, Phil. Mag. 63, 1343 (1991)
M.Z. Kabir, Nucl. Instrum. Methods A 736, 156 (2014)
R.A. Street, Appl. Phys. Lett. 57, 1334 (1990)
S.A. Mahmood, M.Z. Kabir, J. Vac. Sci. Technol. A 29, 031603 (2011)
G. Vincent, A. Chantre, D. Bois, J. Appl. Phys. 50, 5484 (1978)
J. Frey, An experimental and theoretical study of the dark current and X-ray sensitivity of amorphous selenium x-ray photoconductors, PhD thesis, University of Saskatchewan (2012)
M.Z. Kabir, S.-A. Imam, Can. J. Phys. 92, 641 (2014)
G.E. Frank-Kamenetskaya, M.D. Vorontsov, I.P. Kalinkin, Russ. Phys. J. 33, 952 (1990)
H.-Z. Song, G.J. Adriaenssens, E.V. Emelianova, V.I. Arkhipov, Phys. Rev. B 59, 10607 (1999)
K. Koughia, Z. Shakoor, S.O. Kasap, J.M. Marshall, J. Appl. Phys. 97, 033706 (2005)
G. Belev, S.O. Kasap, J. Optoelectron. Adv. Mater. 11, 1053 (2009)
S. Abbaszadeh, A. Tari, W.S. Wong, K.S. Karim, IEEE Trans. Electron. Devices 61, 3355 (2014)
S. Abbaszadeh, N. Allec, S. Ghanbarzadeh, U. Shafique, K.S. Karim, IEEE Trans. Electron. Devices 59, 2403 (2012)
O. Bubon, G. DeCrescenzo, J.A. Raowlands, A. Reznik, J. Non-Cryst. Solids 358, 2431 (2012)
E. Rosencher, V. Mosser, G. Vincent, Phys. Rev. B 29, 1135 (1984)
M.Z. Kabir, J. Appl. Phys. 104, 074506 (2008)
M.Z. Kabir, S.A. Imam, Appl. Phys. Lett. 102, 153515 (2013)
G. Juska, K. Arlauskas, Phys. Status. Solidi. A 59, 389 (1980)
A.K. Bhatnagar, K.V. Reddy, V. Srivastava, J. Phys. D Appl. Phys. 18, L149 (1985)
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The author acknowledges the financial support by NSERC Discovery Grant program.
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Kabir, M.Z. Dark current mechanisms in amorphous selenium-based photoconductive detectors: an overview and re-examination. J Mater Sci: Mater Electron 26, 4659–4667 (2015). https://doi.org/10.1007/s10854-015-2675-2
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DOI: https://doi.org/10.1007/s10854-015-2675-2