Charge transport properties of CdMnTe radiation detectors

Rafiei, R.; Boardman, D.; Reinhard, Mark I.; Sarbutt, A.; Kim, K.; Watt, G.; Uxa, Štěpán; Prokopovich, Dale A.; Belas, E.; Bolotnikov, A. E.; James, R. B.

doi:10.1051/epjconf/20123502005

Cited by 3 publications

(1 citation statement)

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“…The Fermi level energy -0. μ, required for calculation of the I-V characteristic, can be found from the data shown in figure 2. Knowing the resistivity ρ, one can find the concentration of free electrons as n = 1/qρμ n and then the energy of the Fermi level as μ = kTln(N c /n) (0.532 eV at 292 K, for example) accepting μ n = 720 cm 2 (V s) −1 [19].…”

Section: Correlation Of I-v Characteristics With Generation-recombina...mentioning

confidence: 99%

Graphite/CdMnTe Schottky diodes and their electrical characteristics

Kosyachenko

Yatskiv

Yurtsenyuk

et al. 2013

Semicond. Sci. Technol.

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The first Schottky diodes based on n-CdMnTe crystals with pronounced rectifying properties are investigated. It is shown that the I-V characteristics of the diodes fabricated by printing colloidal graphite can be described by the Sah-Noyce-Shockley theory of generation-recombination in the space charge region. Exponential increase of forward current with voltage is limited by a relatively low barrier height at the graphite/CdMnTe contact (∼ 0.4 eV) and a significant series resistance of the crystal bulk (∼ 10 6 at room temperature). Tunneling due to high concentration of uncompensated impurities in investigated Cd 0.9 Mn 0.1 Te crystals (7 × 10 17 cm −3 ) does not allow increasing the reverse bias voltage to the values needed for the operation of x-and γ -ray detectors. High concentration of uncompensated donors is interpreted by the fact that a certain part of the Mn atoms does not substitute for Cd but plays a role of over-stoichiometric impurities. In the case of the presence of a thin intermediate insulator layer in the graphite/CdMnTe contact, a rapid increase in the current for both polarities of high voltage due to the Frenkel-Poole emission is observed. The obtained results shed light on the problems of technology of growing and post-processing CdMnTe crystals regarded as a prospective material for x-and γ -ray detectors.

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Section: Correlation Of I-v Characteristics With Generation-recombina...mentioning

confidence: 99%

Graphite/CdMnTe Schottky diodes and their electrical characteristics

Kosyachenko

Yatskiv

Yurtsenyuk

et al. 2013

Semicond. Sci. Technol.

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Characterization of CdMnTe radiation detectors using current and charge transients

Rafiei¹,

Reinhard²,

Sarbutt³

et al. 2013

J. Semicond.

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Charge transport characteristics of Cd 0:95 Mn 0:05 Te : In radiation detectors have been evaluated by combining time resolved current transient measurements with time of flight charge transient measurements. The shapes of the measured current pulses have been interpreted with respect to a concentration of net positive space-charge, which has resulted in an electric field gradient across the detector bulk. From the recorded current pulses the charge collection efficiency of the detector was found to approach 100%. From the evolution of the charge collection efficiency with applied bias, the electron mobility-lifetime product of n n D .8:5 ˙0:4/ 10 4 cm 2 /V has been estimated. The electron transit time was determined using both transient current technique and time of flight measurements in the bias range of 100-1900 V. From the dependence of drift velocity on applied electric field the electron mobility was found to be n D .718 ˙55) cm 2 /(V s) at room temperature.

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