About the TADeF meeting
The TADeF meeting was born some months ago when some of the members of the current organizing committee were talking about how disconnected we were from other branches of physics. More specifically, we realized that, while we knew about the research done by the members of our groups and some collaborators in the Campus, we were not aware of the vast majority of the topics that other PhD researchers in the UAB were working on.
The main objective of this meeting is to provide a big picture of all the research in Physics at the PhD level that is done in the UAB and surrounding institutes.
With this aim, the meeting will consist mainly of short talks (10'+3') from PhD researchers and three keynote talks from international invited speakers of general interest, as well as a poster session.
The meeting will take place from the 20th of November at 9 am to the 21st of November at 1 pm in the Faculty of Science of the Universitat Autònoma de Barcelona (the room will be soon announced with the programme).
High Temperature Superconductors: Complex materials with novel physics opportunities
Teresa Puig, SUMAN group, ICMAB-CSIC
Superconductivity is a macroscopic quantum phenomenon with outstanding properties and impact in many applications. The quantum nature of superconductivity enables the formation of a condensate at the energy ground state by electron-pairing (Cooper pairs) providing zero resistance materials. Since high temperature superconducting (HTS) materials were discovered 30 years ago, new opportunities were envisaged because large electrical currents without losses could be expected at liquid nitrogen temperatures, however they faced unknown physics and new materials engineering complexities. HTS are strongly correlated systems showing unconventional superconductivity and novel vortex physics appear associated to high thermal fluctuations, larger crystalline anisotropy and nanometric nature of the HTS superconducting parameters.
Beyond the still unsolved questions, nowadays, the international community is able to fabricate HTS materials for high current energy efficient applications (high power cables, wind generators, electrical aviation) and large scale infrastructures (fusion, circular colliders, high frequency NMR).In this presentation, I will introduce the basic principles of superconductivity and discuss the unconventional physics of HTS. I will then present our contributions specially in the area of vortex physics of HTS materials. I will finalize with a brief summary of the present applications of HTS.
Near Infrared Organic Photodetectors based on Enhanced Charge Transfer State Absorption by Photonic Architectures
Martí Gibert-Roca, NANOPTO group, ICMAB-CSIC
Co-Authors: Pau Molet, Agustín Mihi, Mariano Campoy-Quiles
Near infrared photodetectors are key components in many disciplines, from astronomy and material sciences all the way to medical sciences. Current technologies are now striving to include new aspects in this technology such as wearability, flexibility and tuneability. Organic photodetectors easily offer many of those advantages but their relatively high bandgaps hinder NIR operation. In this work, we demonstrate solution processed organic photodetectors with improved NIR response thanks to a nanostructured active layer in the shape of a photonic crystal. The latter strongly increases the charge transfer state absorption, which is normally weak but broadband, increasing the optical path of light, resulting in remarkable photoresponse significantly below the band gap of the blend. We show responsibilities up to 50 mA W-1 at 900 nm for PBTTT:PC70BM based photodetectors. Furthermore, by varying the lattice parameter of the photonic crystal structure, the spectral response of the photodetectors can be easily tuned beyond 1000 nm. Furthermore, our photonic structure that can be easily implemented in the device in a single nanoimprinting step, with minimal disruption of the fabrication process, which makes this approach very promising for upscaling.