University of New Mexico investigation finds manipulated data and images, prompts retractions

A research group at the University of New Mexico has lost at least two papers after an inquiry found evidence of manipulated data. 

One article, “Large-Area Semiconducting Graphene Nanomesh Tailored by Interferometric Lithography,” appeared in 2015 in Scientific Reports, a Springer Nature title, and has been cited 25 times, according to Clarivate Analytics’ Web of Science. 

The other, “Vertical Charge Transfer and Lateral Transport in Graphene/Germanium Heterostructures,” was published in 2017 in the American Chemical Society’s journal Applied Materials & Interfaces. It has been cited twice.

The senior author on both articles was Sanjay Krishna, who has since moved to the Ohio State University, where he is the George R. Smith Chair in Electrical and Computer Engineering. 

The retraction notice for the paper in Scientific Reports states: 

The Editors have retracted this article following an investigation by the University of New Mexico which established that:

Figure 2A and 2G contain data points that cannot be substantiated;

Figure 3A-F and the corresponding histogram data contain images in which contrast has been adjusted or other nonlinear image enhancements made, resulting in images that have smaller feature sizes than were actually present;

The image shown in Figure S3E does not originate from the same sample as other panels in this figure; Figure S3E appears to also have been manipulated in a manner similar to Figure 3;

The Raman spectral data in Figures. 4A-C are shifted along the X-axis to produce a systematic shift of the G-band with stated feature size. The spectral data shown in Figure 4C which depict a shift in the G-band peaks irrespective of location on the structures cannot be substantiated;

Figures 5B and 5C, as well as the red curve in Figure 5D cannot be substantiated;

In Table I, rows “Min Neck Width (nm)”, “ON/OFF Ratio”, “Mobility (cm2/V.s)”, and “Band gap (meV)” in the column “Interferometric Litho” cannot be substantiated;

Figure 6 and Figure S5 cannot be substantiated.

Sanjay Krishna, Francesca Cavallo and Steven R. J. Brueck agreed with the retraction and its wording. Alireza Kazemi and Terefe G. Habteyes did not respond to the correspondence about the retraction. The Editors were not able to obtain current email addresses for Xiang He, Seyedhamidreza Alaie, Javad Ghasemi, and Noel Mayur Dawson.

The notice in ACS AM&I is similar: 

The Editor retracts this article at the request of The University of New Mexico. During a research integrity investigation, The University of New Mexico uncovered problematic information that pertains to this paper.

The investigation determined that the Figures 4b–f and 5a,b, and the supplemental Figures S3c,d and S5 are compromised. More specifically:

Figure 4, panel b (red curve, “Gr/Ge”), and panels c–f of this manuscript contain problematic data. The red curve in panel b (“Gr/Ge” curve) is depicted as being from a region of the sample where the channels contained the graphene/germanium structures when, in fact, the correspondence of the measurement region of the sample to the Gr/Ge region of the sample was not established. The shape of the red curve in panel b shows inflated values of voltages. Problematic data points were added to panels c–f.

Figure 5, panels a and b of this manuscript contain problematic data. Images of the device structures in panel a are real. However, the data points shown were selected to present points that show the desired slopes for the two classes of materials. The full set of measurements taken, when systematically viewed, do not support the proposition “stated”. The error bars shown in panel a do not represent any true measure of uncertainty.

Figure S3, panels c and d, in the Supporting Information for this manuscript, published online, present data as being from a region of the sample where the channels contained the graphene/germanium structures when, in fact, the correspondence of the measurement region of the sample to the Gr/Ge region of the sample was not established.

Figure S5 in the Supporting Information for this manuscript, published online, contains data that are not representative of the entire set of measurements taken, and the data presented have been selected to emphasize desired trends.

Based on these issues, The University of New Mexico has requested retraction of this paper.

Krishna declined to provide details to Retraction Watch about the case, stating: 

Unfortunately I am not at liberty to discuss this as this was an investigation conducted by the University of New Mexico.

Our email to the associate vice president for research at the University of New Mexico did not receive a response.

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