Mechanisms contributing to dark current across metal/CdMnTe/metal structures

Journal Article · 09 September 2019 · Proceedings of SPIE - The International Society for Optical Engineering

DOI: https://doi.org/10.1117/12.2530444 · OSTI ID:1604906

Sklyarchuk, Valerii M. ^[1]; Fochuk, Petro ^[1]; Solodin, Serhii ^[1]; Zakharuk, Zinaida ^[1]; Rarenko, Anna ^[1]; Bolotnikov, A. E. ^[2]; James, Ralph B. ^[3]

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1. Yuriy Fedkovych Chernivtsi National Univ. (Ukraine)
2. Brookhaven National Lab. (BNL), Upton, NY (United States)
3. Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Brookhaven National Lab. (BNL), Upton, NY (United States)

The study of the electro-physical properties of n-type semi-insulating crystals of indium-doped Cd(Mn)Te solid solution with a resistivity ~ (4÷5)×10¹⁰ Ohm×cm at T = 300 K was carried out. The structures both with an ohmic (In/Cd(Mn)Te/In) contacts and with the rectifying (Ni/Cd(Mn)Te/In) contact were fabricated. It was found that for the Ni/Cd(Mn)Te/In structure, the main mechanisms of charge transport were: the generation currents in the space-charge region, space-charge limited currents (SCLC) at high voltages, and the Ohm’s law was valid only on initial section the of the volt-ampere characteristics (I-VC). Calculation of the generation current dependence on the voltage according to the theory of Sah-Noyce-Shockley was carried out. For the In/Cd(Mn)Te/In structure it was observed the I-VC initial section, where the Ohm’s law was implemented, and the SCLCs with the participation of deep centers (traps) in semiinsulating crystal - at greater voltages. The concentration of deep centers (Nt ~ 7.4×10¹⁰ cm^-3 ) responsible for the trap mechanism in SCLC In/Cd(Mn)Te/In structures was calculated. The energy position Et of the deep levels was determined (provided that the energy was calculated from the valence band edge, Et = 0.89÷0.9 eV). It was discussed and grounded the assumption that SCLC was the main mechanism limiting the operating voltages and, consequently, the use of Cd(Mn)Te-based ionizing-radiation detectors with ohmic contacts.

• Research Organization: Savannah River Site (SRS), Aiken, SC (United States); Savannah River National Laboratory (SRNL), Aiken, SC (United States)
• Sponsoring Organization: USDOE Office of Environmental Management (EM)
• Grant/Contract Number: AC09-08SR22470
• OSTI ID: 1604906
• Report Number(s): SRNL-STI-2019-00484; TRN: US2104344
• Journal Information: Proceedings of SPIE - The International Society for Optical Engineering, Vol. 11114; ISSN 0277-786X
• Publisher: SPIECopyright Statement
• Country of Publication: United States
• Language: English