On the origin of the improved hydrogen evolution reaction in Mn- and Co-doped MoS.

In the field of hydrogen production, MoS demonstrates good catalytic properties for the hydrogen evolution reaction (HER) which improve when doped with metal cations. However, while the role of sulfur atoms as active sites in the HER is largely reported, the role of metal atoms ( molybdenum or the dopant cations) has yet to be studied in depth. To understand the role of the metal dopant, we study MoS thin films doped with Co and Mn ions.

Amorphous ZnO/PbS Quantum Dots Heterojunction for Efficient Responsivity Broadband Photodetectors.

The integration of lead sulfide quantum dots (QDs) with a high-conductivity material that is compatible with a scalable fabrication is an important route for the applications of QD-based photodetectors. Herein, we first developed a broadband photodetector by combining amorphous ZnO and PbS QDs, forming a heterojunction structure. The photodetector showed detectivity up to 7.

High plasticity reversible resistive switching in heteroepitaxial metal/CeO2-x /Nb:SrTiO3/Ti/Pt structures.

We report on the characterization of resistive switching devices based on epitaxial CeO2 thin films as a functional material. CeO2 epitaxial thin films were grown by the pulsed laser deposition technique on conductive substrates. Platinum and titanium nitride top electrodes (TE) were successively deposited.

Role of Associated Defects in Oxygen Ion Conduction and Surface Exchange Reaction for Epitaxial Samaria-Doped Ceria Thin Films as Catalytic Coatings.

Samaria-doped ceria (SDC) thin films are particularly important for energy and electronic applications such as microsolid oxide fuel cells, electrolyzers, sensors, and memristors. In this paper, we report a comparative study investigating ionic conductivity and surface reactions for well-grown epitaxial SDC films varying the samaria doping concentration. With increasing doping above 20 mol % of samaria, an enhancement in the defect association is observed by Raman spectroscopy.

Bias assisted scanning probe microscopy direct write lithography enables local oxygen enrichment of lanthanum cuprates thin films.

Scanning probe bias techniques have been used as a method to locally dope thin epitaxial films of La(2)CuO(4) (LCO) fabricated by pulsed laser deposition. The local electrochemical oxidation of LCO very efficiently introduces interstitial oxygen defects in the thin film. Details on the influence of the tip voltage bias and environmental conditions on the surface morphology have been investigated.

Defective interfaces in yttrium-doped barium zirconate films and consequences on proton conduction.

Yttrium-doped barium zirconate (BZY) thin films recently showed surprising electric transport properties. Experimental investigations conducted mainly by electrochemical impedance spectroscopy suggested that a consistent part of this BZY conductivity is of protonic nature. These results have stimulated further investigations by local unconventional techniques.

Effect of doping on surface reactivity and conduction mechanism in samarium-doped ceria thin films.

A systematic study by reversible and hysteretic electrochemical strain microscopy (ESM) in samples of cerium oxide with different Sm content and in several working conditions allows disclosing the microscopic mechanism underlying the difference in electrical conduction mechanism and related surface activity, such as water adsorption and dissociation with subsequent proton liberation. We have measured the behavior of the reversible hysteresis loops by changing temperature and humidity, both in standard ESM configuration and using the first-order reversal curve method. The measurements have been performed in much smaller temperature ranges with respect to alternative measuring techniques.

Design, fabrication and characterization of a capacitive micromachined ultrasonic probe for medical imaging.

In this paper we report the design, fabrication process, and characterization of a 64-elements capacitive micromachined ultrasonic transducer (cMUT), 3 MHz center frequency, 100% fractional bandwidth. Using this transducer, we developed a linear probe for application in medical echographic imaging. The probe was fully characterized and tested with a commercial echographic scanner to obtain first images from phantoms and in vivo human body.

Vibration maps of capacitive micromachined ultrasonic transducers by laser interferometry.

In this letter, a 1.8-mm x 1.8-mm capacitive micromachined ultrasonic transducer (CMUT) element is experimentally characterized by means of optical measurements.