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PLoS One
PLoS One
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PLOS ONE
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10.1371/journal.pone.0288213
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Expression of Concern
Expression of Concern: Electrical Study of Trapped Charges in Copper-Doped Zinc Oxide Films by Scanning Probe Microscopy for Nonvolatile Memory Applications
The PLOS ONE Editors
29 6 2023
2023
29 6 2023
18 6 e0288213© 2023 The PLOS ONE Editors
2023
The PLOS ONE Editors
https://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Electrical Study of Trapped Charges in Copper-Doped Zinc Oxide Films by Scanning Probe Microscopy for Nonvolatile Memory Applications
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pmcAfter publication of this article [1], concerns were raised that previously published work [2–4] that studied similar materials systems was not cited and discussed in article [1].

Additionally, contrary to the declaration in the Data Availability Statement, and in violation of PLOS’ Data Availability Policy, the original data files supporting the article’s results were not provided with the article. The authors did not provide the original raw data supporting results reported in this article [1] during follow-up discussions.

Upon follow up the PLOS ONE Editors were also unable to obtain information about where the experimental work was carried out.

Given that this article [1] does not comply with PLOS’ Data Availability Policy, the PLOS ONE Editors issue this Expression of Concern.
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References

1 Su T , Zhang H (2017) Electrical Study of Trapped Charges in Copper-Doped Zinc Oxide Films by Scanning Probe Microscopy for Nonvolatile Memory Applications. PLoS ONE 12 (1 ): e0171050. doi: 10.1371/journal.pone.0171050 28135335
2 Herng T.S. , Wong M.F. , Qi D. , Yi J. , Kumar A. , Huang A. , Kartawidjaja F.C. , Smadici S. , Abbamonte P. , Sánchez-Hanke C. , Shannigrahi S. , Xue J.M. , Wang J. , Feng Y.P. , Rusydi A. , Zeng K. and Ding J. (2011), Mutual Ferromagnetic–Ferroelectric Coupling in Multiferroic Copper-Doped ZnO. Adv. Mater., 23 : 1635–1640. doi: 10.1002/adma.201004519 21472791
3 Wong Meng Fei , Herng Tun Seng , Zhang Zhongkun , Zeng Kaiyang , Ding Jun ; Stable bipolar surface potential behavior of copper-doped zinc oxide films studied by Kelvin probe force microscopy. Appl. Phys. Lett. 6 December 2010; 97 (23 ): 232103. doi: 10.1063/1.3521281
4 Kumar Amit , Herng Tun Seng , Zeng Kaiyang , and Ding Jun Bipolar Charge Storage Characteristics in Copper and Cobalt Co-doped Zinc Oxide (ZnO) Thin Film ACS Applied Materials & Interfaces 2012 4 (10 ), 5276–5280 doi: 10.1021/am301220h 22948114