Research Highlights

A general microscopic theory was developed to identify multiple modes in Raman spectra and to connect their weights to the superconducting gap structure in hole doped BaFe_2­As₂. This work shows the synergistic benefit of tying computational developments directly to experimental observables.

S. Maiti, T. A. Maier, T. Böhm, R. Hackl, P.  J. Hirschfeld, "Probing the pairing interaction and multiple Bardasis-Schrieffer modes using Raman spectroscopy,"  Phys. Rev. Lett. 117, 257001 (2016). DOI: 10.1103/PhysRevLett.117.257001

Previously, free-standing three-dimensional nanostructures have been fabricated by focused electron beam induced deposition, yielding materials that contain a significant amount of carbon in addition to the desired metal. Now an in-situ purification method that uses electron beams and water vapor leads to purely metallic structures. 

R. Winkler, F.-P. Schmidt, U. Haselmann, J. D. Fowlkes, B. B. Lewis, G. Kothleitner, P. D. Rack, H. Plank, "Direct-write 3D nanoprinting of plasmonic structures," ACS Applied Materials & Interfaces (2016). DOI:10.1021/acsami.6b13062.

Enhancing heat dissipation at the interfaces of nanoelectronic devices is a significant challenge for 2D electronics. First principles calculations explain the mechanisms of phonon transport at such interfaces.

Z. Yan, L. Chen, M. Yoon, and S. Kumar, Applied Materials & Interfaces, [online] (2016). | DOI:10.1021/acsami.6b10608

Photogenerated excitons need to be weakly bound in order to improve the conversion efficiency from light to electricity. A structure consisting of a single layer of CdSe/ZnS quantum dots on a monoloayer of WS­₂ enables the creation of such excitons that are several times more weakly bound than those in WS₂ alone. 

A. Boulesbaa, K. Wang, M. Mahjouri-Samani, M. Tian, A. A. Puretzky, I. Ivanov, C. M. Rouleau, K. Xiao, B. G. Sumpter, D. B. Geohegan, J. Am. Chem. Soc., 138, 14713 (2016) | DOI: 10.1021/jacs.6b08883

Acetonitrile, one of the most stable nitriles, has been converted to a graphitic polymer at room temperature and high pressure, rather than at high temperature and using catalysis. This was observed using neutron scattering (SNS’s SNAP instrument) with CNMS contributing through in-situ Raman spectroscopy, dielectric spectroscopy, electron microscopy, and the development of the temperature-pressure phase diagram.

H. Zheng et al., Angew. Chem. Int. Ed., 55, 1 (2016). | DOI: 10.1002/anie.201606198l

An in-situ scanning transmission electron effort using a tip containing metallic lithium was used to discover a self-limiting phase transformation between a solid electrolyte (LLZO) and Li-metal. This approximately five unit-cell thick layer prevents further interfacial reactions.

C. Ma et al., Nano Letters, 16, 7030 (2016). | DOI: 10.1021/acs.nanolett.6b03223

A new computational approach shows how isotopic substitution in polymer-based photovoltaics affects charge transfer. In particular, an unexpected nuclear quantum effect caused by side-chain deuteration in P3HT/PCBM blends strongly influences the open circuit voltage these photovoltaics.

L. Wang et al.,, JCTC 12, 4487 (2016). | DOI: 10.1021.acs.jctc.6b00126

A nanostructured “carbon spikes” catalyst electrochemically convert CO₂ to ethanol under ambient conditions with a 63% yield (colloquially referred to as the “CO₂-to-beer conversion”).

Y. Song, R. Peng, D. Hensley, P. V. Bonnesen, L. Liang, Z. Wu, H. M. Meyer III, M. Chi, B. Sumpter, and A. J. Rondinone, ChemistrySelect 1, 6055 (2016). | DOI: 10.1002/slct.201601169

Introducing tailored interfaces into two-dimensional MoS₂ nanosheets enhances their photocatalytic water splitting activity by 400%. These interfaces are a consequence of an annealing-controlled coexistence of different crystal phases of MoS₂. 

R. Peng et al., ACS Catalysis 6, 6723 (2016). | DOI: 10.1021/acscatal.6b02076