RHK PanScan

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Image of the Month
Posted Date: April 1, 2016

Figure 1: Adsorption of DDQT molecules on Au(111) in the intermediate coverage regime. STM image [set point 100 mV, 5 pA] of a large areafeaturing a finite-sized 2D crystal of DDQT with individual DDQT dimers in the vicinity (J. Phys. Chem. C 2015, 119, 26959−26967)

Charge transport in electronic applications involving molecular semiconductor materials strongly depends on the electronic properties of molecular-scale layers interfacing with external electrodes. In particular, local variations in molecular environments can have a significant impact on the interfacial electronic properties. In this study, we use scanning tunneling microscopy and spectroscopy to investigate the self-assembly regimes and resulting electronic structures of alkyl-substituted quaterthiophenes adsorbed on the Au(111) surface. We find that at dilute molecular concentrations, dimerized cis conformers were formed, while at higher concentrations corresponding to small fractions of a submonolayer, the molecular conformation converted to trans, with the molecules self-assembled into ordered islands. At approximately half-monolayer concentrations, the structure of the self-assembled islands transformed again showing a different type of the trans conformation and qualitatively different registry with the Au(111) lattice structure. Molecular distributions are observed to vary significantly due to variations in local molecular environments, as well as due to variations in the Au(111) surface reactivity. While the observed conformational diversity suggests the existence of local variations in the molecular electronic structure, significant electronic differences are found even with molecules of identical apparent adsorption configurations. Our results show that a significant degree of electronic disorder may be expected even in a relatively simple system composed of conformationally flexible molecules adsorbed on a metal surface, even in structurally well-defined self-assembled molecular layers.

Dmitry A. Kislitsyn, Benjamen N. Taber, Christian F. Gervasi, Stefan C. B. Mannsfeld, Lei Zhang,
Alejandro L. Briseno, and George V. Nazin (J. Phys. Chem. C 2015, 119, 26959−26967)
Images and data graciously provided by George Nazin, University of Oregon, Eugene, Oregon.

RHK PanScan Freedom Microscope

Control System:
RHK Technology Control System

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Panscan Freedom SPM,  VT Beetle
Posted Date: March 15, 2016

RHK Technology has recently installed the first PanScan Freedom AFM/STM system with their latest cryostat option, offering a 9K base temperature. The system was installed at the University of New Hampshire, in the laboratory of Prof. Shawna Hollen.   Besides the standard PanScan Freedom architecture, this unique system included a custom preparation chamber designed to provide a five-point probe measurement station, having three degrees of freedom for probe positions. It has also been equipped with a top-view port for probe positioning.

PanScan Freedom Cryogen-Free LT AFM/STM


“I chose the PanScan Freedom after seeing the technology both at APS 2015 and the RHK factory. The ability to continue my low-temperature research without the concerns of sourcing liquid cryogens was one of the deciding factors. Working with the RHK team has been great so far, and my students really appreciated the time and care the installation scientist spent training them. We look forward to executing our research exploring the properties and functionalization of 2D materials using the unique tools developed by and with RHK.” — Prof. Hollen 

RHK Technology looks forward to installing many more of these systems in the coming months, with installations planned in China, Germany, Australia, and the USA. RHK Technology will also be demonstrating the 9K PanScan Freedom system at the upcoming APS meeting in Baltimore, MD. To thank it’s customers for their continued support, there will be a users reception to be held at the Hilton Baltimore during the annual APS meeting. Stop by booth 510 to ask about the details.

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Panscan Freedom SPM,  VT Beetle
Event Date: March 14, 2016

Mar 14-18
American Physical Society March 2016

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Panscan Freedom SPM,  VT Beetle
Event Date: March 6, 2016

Mar 6-11
80th Annual Meeting of the DPG and DPG Spring Meeting

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