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Title: Microinhomogeneities in Semi-Insulating Cd(Zn)Te

Here, we investigated the temperature dependences (TDs) in the range of 290-423 K for the Hall constant R H and the Hall carrier mobility μn (σ R H) in semi-insulating Cd 0.9 Zn 0.1 Te:In (CZT) crystals. As-grown, CZT material has nonequilibrium distributions of native and impurity-related defects. Thus, before taking any measurements, the samples were kept inside the test chamber in the dark at 423 K to reach an equilibrium state at T <; 423 K. For all the tested samples, the R H TD could be described by two activation energies. At the transitional point, the TD of the carrier mobility also changes from “normal” at high temperatures to “exponential” at low temperatures. The latter is a result of the collective effect of drift barriers due to microinhomogeneity. Therefore, only the high-temperature activation energies can be assigned to the ionization energies of the compensated deep donors (ε D). For different samples, the values for ε D 0 (at absolute zero) were found to be in the range of 0.50-0.78 eV, and the degree of donor compensation [D +]/[D] is between 0.3 and 0.98. The low-temperature region, where there are strong effects of crystal microinhomogeneities, cannot be used tomore » characterize the ionization energy of donors. Therefore, we describe the activation energy as ε 1 = ε D - αε b, where ε b is the drift barrier height found from the TD of the carrier mobility and α takes a value close to unity. Values of ε b for our studied samples lie within (0.05-0.35) eV.« less
Authors:
ORCiD logo [1] ;  [2] ;  [1] ;  [1] ;  [3] ;  [4] ;  [4]
  1. Chernivtsi National Univ., Chernivtsi (Ukraine)
  2. National Univ. of Water Management and Natural Resources Use, Rivne (Ukraine)
  3. Institute of Single Crystals NASU, Kharkiv (Ukraine)
  4. Brookhaven National Lab. (BNL), Upton, NY (United States)
Publication Date:
Report Number(s):
BNL-114808-2017-JA
Journal ID: ISSN 0018-9499; R&D Project: 21746; TRN: US1800364
Grant/Contract Number:
SC0012704
Type:
Accepted Manuscript
Journal Name:
IEEE Transactions on Nuclear Science
Additional Journal Information:
Journal Volume: 64; Journal Issue: 10; Journal ID: ISSN 0018-9499
Publisher:
IEEE
Research Org:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org:
USDOE National Nuclear Security Administration (NNSA), Office of Nonproliferation and Verification Research and Development (NA-22)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; Cd(Zn)Te; defects; electrical characterization (EC); Hall effect; semiconductor
OSTI Identifier:
1412784

Fochuk, P., Nykoniuk, Y., Zakharuk, Z., Kopach, O., Kovalenko, N., Bolotnikov, A. E., and James, Ralph B.. Microinhomogeneities in Semi-Insulating Cd(Zn)Te. United States: N. p., Web. doi:10.1109/TNS.2017.2748700.
Fochuk, P., Nykoniuk, Y., Zakharuk, Z., Kopach, O., Kovalenko, N., Bolotnikov, A. E., & James, Ralph B.. Microinhomogeneities in Semi-Insulating Cd(Zn)Te. United States. doi:10.1109/TNS.2017.2748700.
Fochuk, P., Nykoniuk, Y., Zakharuk, Z., Kopach, O., Kovalenko, N., Bolotnikov, A. E., and James, Ralph B.. 2017. "Microinhomogeneities in Semi-Insulating Cd(Zn)Te". United States. doi:10.1109/TNS.2017.2748700. https://www.osti.gov/servlets/purl/1412784.
@article{osti_1412784,
title = {Microinhomogeneities in Semi-Insulating Cd(Zn)Te},
author = {Fochuk, P. and Nykoniuk, Y. and Zakharuk, Z. and Kopach, O. and Kovalenko, N. and Bolotnikov, A. E. and James, Ralph B.},
abstractNote = {Here, we investigated the temperature dependences (TDs) in the range of 290-423 K for the Hall constant RH and the Hall carrier mobility μn (σ RH) in semi-insulating Cd0.9 Zn0.1 Te:In (CZT) crystals. As-grown, CZT material has nonequilibrium distributions of native and impurity-related defects. Thus, before taking any measurements, the samples were kept inside the test chamber in the dark at 423 K to reach an equilibrium state at T <; 423 K. For all the tested samples, the RH TD could be described by two activation energies. At the transitional point, the TD of the carrier mobility also changes from “normal” at high temperatures to “exponential” at low temperatures. The latter is a result of the collective effect of drift barriers due to microinhomogeneity. Therefore, only the high-temperature activation energies can be assigned to the ionization energies of the compensated deep donors (εD). For different samples, the values for εD0 (at absolute zero) were found to be in the range of 0.50-0.78 eV, and the degree of donor compensation [D+]/[D] is between 0.3 and 0.98. The low-temperature region, where there are strong effects of crystal microinhomogeneities, cannot be used to characterize the ionization energy of donors. Therefore, we describe the activation energy as ε1 = εD - αεb, where εb is the drift barrier height found from the TD of the carrier mobility and α takes a value close to unity. Values of εb for our studied samples lie within (0.05-0.35) eV.},
doi = {10.1109/TNS.2017.2748700},
journal = {IEEE Transactions on Nuclear Science},
number = 10,
volume = 64,
place = {United States},
year = {2017},
month = {9}
}