A strain tunable single-layer MoS2 photodetector

Lets take a single layer of MoS2. Lets attach it to a surface in such a way that it can be stretched (or compressed) and there you have it: A strain tunable single-layer MoS2 photodetector. A device which uses strain to change the electrical and optical properties of 2D materials. In particular they’ve proven that with this method, they can reversibly change the photoresponsivity, the response time and the spectral bandwidth of single layered MoS2.

At Dr. Castellanos Lab, they are excelling at beautiful and elegant research. “… we demonstrated that applying tensile biaxial strain to the MoS2 device can be an effective strategy to increase both the responsivity and the wavelength bandwidth of the photodetector (at the expense of a slower response time), while compressive strain can be exploited to yield faster photodetectors (although with a lower photoresponse and with a narrower wavelength bandwidth). This adaptable optoelectronic performance of this device can be very useful to adjust the photodetector operation to different lighting conditions, similarly to human eye adaptability (scotopic vision during the night vs. photopic vision during the daylight).

Their research is a collaboration between ICMM-CSIC, Imdea Nanociencia and the State Key Laboratory of Tribology, Tsinghua University, Beijing and has been recognized with the inner cover of Materials Today.

Swiss Army SPM

Mario Lanza proposes a new scanning probe microscopy technique that can examine local phenomena, and conductive atomic force microscopy, in particular, study local electromechanical properties. Check it in Nature Electronics!

In this schematic illustration we did to illustrate his proposition, it is shown how this setup, would allow multiple experiments to be carried out simultaneously and under vacuum conditions.

 

It comes in colors everywhere

A research group at IMDEA Nanociencia (together with the University of Grenoble and Berkeley) have presented a new switchable iron-based coordination polymer, which works as a reversible acetonitrile sensor.

Coordination polymers are emerging as molecular sensing materials for a variety of reasons: they are not toxic, environmentally friendly and above all, they’re highly responsive to a wide variety of external stimuli.

This polymer in particular, the unutterable {[Fe(H2O)2(CH3CN)2(pyrazine)](BF4)2·(CH3CN)2}, happens to be an excellent acetonitrile sensor: a toxic volatile organic compound, that makes its detection a major issue. The desorption of interstitial acetonitrile changes reversibly the color of the polymer together with its electronic and magneto–structural properties.

On request of José Sánchez Costa and Enrique Burzuri we made this picture, showing the reversibility of the process, that made it to the back cover of Chemical Science.

 

Magnetism and odd numbers

We’ve talked about Prof. Dr. Patrick Maletinsky’s research ([1], [2]) in several ocasions. His research group is excelling at the development of new microscopies. Recently they’ve pushed the envelope another step further by for the first time “measuring the magnetic properties of atomically thin van der Waals materials on the nanoscale”. 2D materials are going to play a key role in the next technological revolution. And the we need tools to study and characterize these systems.

Quantum Sensing Lab together with several groups at the university of Geneva, have determined the magnetic properties of single atomic layers of chromium triiodide (CrI3).

By carefully doing this, they’ve found that the magnetic properties of this material depends on the number of layers of CrI3: an even number of layers produces no magnetic fields while an odd number of them, produces the same fields as a single CrI3 layers. This results have been published in Science.

We made this picture to illustrate this amazing step forward with the help of Patrick Maletinsky and Lucas Thiel. [Read more at UniBas]

Let there be light!

A research team at TU Wien ( Matthias Paur, Aday J. Molina-Mendoza, et al. ) together with groups from Germany and Japan, have developed a new type of light-emitting diode. What’s exciting about it? That it produces light from the decay of an exciton. An exciton is a bound state of an electron and an electron hole which orbit around one another. This electron-hole pairs can be created by applying electrical charges and when these pairs recombine, they produce energy in the form of light.

To make it even more exotic, they’ve created this diode by producing excitons in two dimensional materials. This systems have shown to be not only a great way to study this quasiparticles but also have a great potential to became a usable device. Just to name one of its characteristics, the wavelength of the light emitted by this devices is highly tunable.

With the supervision of Aday Molina-Mendoza, we did this picture to illustrate the emission process. This research has been published in Nature Communications.

Do electric neurons dream of…

This is getting out of hand. At LanzaLab they try to emulate the behavior of neuron synapses using multilayered hexagonal boron nitride (h-BN) . An interesting paradigm states that a biologically inspired computing architecture, will overcome the energy and efficiency limitations of classic computing architectures. To carry it out will require the design of electronic neurons and synapses. There are several features to be copied from mother’s nature design: it has to be fast, energetically efficient and it has to have a long term/short term plasticity. And at Lanzalab, they’ve achieved most of them. Their h-BN devices consume between 0.1 fW and 600 pW and they have a truly fast response: around 10ns.

We made this image supervised by Prof. Mario Lanza to illustrate their work published in Nature Electronics.

SAMS-4

SAMS-4 is the 4th edition of the Workshop on Scattering of Atoms and Molecules from Surfaces, which is organized every three years. Previous editions were held in Rehovot (Israel, 2010), Postdam (Germany, 2013) and Bergen (Norway, 2016) with great success. This year, organized by Prof. Daniel Farías the event will be held in Madrid.

Stefan Bilan kindly asked me to make a picture for their website. And this is what I did.

Flying metal!

Imagine a bulk of metal (titanium, zirconium and nickel) at 1100ºC flowing from a crucible and getting in contact with a cold fast spinning wheel. In principle, it sounds like a bad idea. And it is also the way the team lead by Dr. Laurent Marot produces amorphous metallic ribbons. Their main areas of application are transformer cores and active solder foils.

The company Endress+Hauser came to the University of Basel, looking for a solder foil that met its requirements. Basel University developed and is still improving this production method, reaching high levels of quality and reducing the process energy cost. According to Laurent Marot: “The cooperation is beneficial for both sides. Endress Hauser gets high-quality metallic glasses that they can use in their production of pressure sensors, and the university can use the revenue to finance their research. “

We did this picture, supervised by Dr. Laurent Marot to illustrate the process.

Demoreel 2017-2018

This demo has taken two years… documentaries, advertising, covers, pictures… we’ve been pretty busy lately.