María Bernechea
University of Zaragoza, Institute of Nanoscience of Aragon, Department Member
- Cardiff University, Cardiff School of Engineering, Faculty Memberadd
- Dr. Bernechea joined the Institute of Nanoscience of Aragon in 2017. Before she was working as lecturer at Cardiff Sc... moreDr. Bernechea joined the Institute of Nanoscience of Aragon in 2017. Before she was working as lecturer at Cardiff School of Engineering were she joined in 2016 from the Institute of Photonic Sciences. She has a broad research experience, covering different areas of chemistry and materials science. She is interested in the development of materials for clean energy applications such as solar cells, thermoelectric devices, or photocatalysis.
Dr. Bernechea obtained her PhD in 2006 for her work on organometallic chemistry. After that, during her postdoctoral experience she gained knowledge about the synthesis and characterisation of nanomaterials.
She worked on the synthesis and characterisation of metallic nanoparticles for their use in catalytic processes, such as C-C coupling reactions in water or as electrocatalysts in polymeric membrane fuels cells.
In the last years she has been working on the synthesis of colloidal nanocrystalline semiconductors for their use in optoelectronic devices such as photodetectors and solar cells. In this field, one of her main areas of interest has been the development of materials based on non-toxic, earth-abundant elements for their use in environmentally friendly, low-cost solar cells.
ORCID: http://orcid.org/0000-0003-2800-6845edit
Research Interests:
The brightness, large absorption cross-section and flexibility of colloidal nanocrystal quantum-dots (QDs) make these materials promising candidates for light harvesting applications. The difficulty of efficiently extracting... more
The brightness, large absorption cross-section and flexibility of colloidal nanocrystal quantum-dots (QDs) make these materials promising candidates for light harvesting applications. The difficulty of efficiently extracting photogenerated carriers from the QDs however drastically limits the power conversion efficiency of NQD solar cells. A possible way to circumvent these issues is to engineer hybrid devices that utilize alternative energy transfer schemes to effectively separate light harvesting and charge extraction in different materials. In this context, hybrid bulk semiconductor/QDs devices coupled through near-field resonant energy transfer offer a promising route towards low cost ultra-thin photovoltaics. In this work, we demonstrate non-radiative resonance energy transfer between lead sulphide (PbS) QDs and bulk silicon using time-resolved spectroscopy.
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In this article, we offer an analysis of point-source water pollution governance in the European agri-food sector. Specifically, we tackle the case study of the wine industry in Aragon (Spain) through the lenses of the networks of action... more
In this article, we offer an analysis of point-source water pollution governance in the European agri-food sector. Specifically, we tackle the case study of the wine industry in Aragon (Spain) through the lenses of the networks of action situations approach. We unveil key strategic decisions of wine producers in relation to compliance with water discharge regulations and explore the feasibility and effectiveness of potential solutions. According to our quantitative and qualitative analyses, the problem of peak load discharges in the sector can be explained by the strategic behavior of wine producers in the context of enforcement deficits, as well as by particularities of the wine production process, and controversies around the construction and management of public treatment plants. Coordination among wine producers and public treatment plant managers to invest in in-house treatment infrastructure or to smooth discharges out so they fit the capacity of treatment plants would be a pr...
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Martinez, L., Bernechea, M., de Arquer, FPG and Konstantatos, G.(2011), Near IR-Sensitive, Non-toxic, Polymer/Nanocrystal Solar Cells Employing Bi 2 S 3 as the Electron Acceptor. Advanced Energy Materials. doi: 10.1002/aenm. 201100441
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ABSTRACT Semiconductor Quantum Dots (QDs) are promising materials for photovoltaic applications because they can be engineered to absorb light from visible to near infrared and single absorbed photons can generate multiple excitons.... more
ABSTRACT Semiconductor Quantum Dots (QDs) are promising materials for photovoltaic applications because they can be engineered to absorb light from visible to near infrared and single absorbed photons can generate multiple excitons. However, these materials suffer from low carrier mobility, which severely limits the prospects of efficient charge extraction and carrier transport. We take advantage of the optical properties of QDs and overcome their drawback by using a hybrid photovoltaic device. This photovoltaic configuration exploits the absorption of solar photons in the QDs and the transfer of excitons from the QDs to a silicon p-n junction. We study the Resonance Energy Transfer (RET) mechanism to inject excitons from the QDs into the depletion layer of a silicon p-n junction. Lead sulphide (PbS) nanocrystals are deposited onto the silicon substrate and the efficiency of Resonance Energy Transfer (RET) from the PbS nanoparticles to bulk silicon is investigated. We study the efficiency of this transfer channel between the PbS nanocrystals and silicon by varying their separation distance. These results demonstrate RET from colloidal quantum dots to bulk silicon. Temperature measurements are also presented and show that the RET efficiency is as high as 44% at room temperature. Such a hybrid photovoltaic device makes a potentially inexpensive scheme for achieving highefficiency and low-cost solar-cell platforms.
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ABSTRACT In this work, we investigate the temperature dependence of the photoluminescence decay and integrated photoluminescence of oleic acid capped PbS quantum dots with diameters ranging from 2.3 to 3.5 nm over a broad temperature... more
ABSTRACT In this work, we investigate the temperature dependence of the photoluminescence decay and integrated photoluminescence of oleic acid capped PbS quantum dots with diameters ranging from 2.3 to 3.5 nm over a broad temperature range (6−290 K). All the investigated samples exhibit similar behavior, consisting of three different temperature regimes. The low-temperature regime (<180 K) is characterized by an increase in the average decay rate and a decrease in integrated photoluminescence. The intermediate regime (∼180−250 K) is described by an enhancement in the photoluminescence intensity and a decrease in the average decay rate. The high-temperature regime (>250 K) is governed by quenched photoluminescence intensity and acceleration in the average lifetimes. We propose a three-level system, composed of bright, dark, and surface states, which describes the observed photoluminescence dynamics of oleic acid capped PbS QDs.
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ABSTRACT In the last decade, solution-processed quantum dot/nanocrystal solar cells have emerged as a very promising technology for third-generation thin-film photovoltaics because of their low cost and high energy-harnessing potential.... more
ABSTRACT In the last decade, solution-processed quantum dot/nanocrystal solar cells have emerged as a very promising technology for third-generation thin-film photovoltaics because of their low cost and high energy-harnessing potential. Quantum dot solar cell architectures developed to date have relied on the use of bulk-like thin films of colloidal quantum dots. Here, we introduce the bulk nano-heterojunction concept for inorganic solution-processed semiconductors. This platform can be readily implemented by mixing different semiconductor nanocrystals in solution and allows for the development of optoelectronic nanocomposite materials with tailored optoelectronic properties. We present bulk nano-heterojunction solar cells based on n-type Bi2S3 nanocrystals and p-type PbS quantum dots, which demonstrate a more than a threefold improvement in device performance compared to their bilayer analogue, as a result of suppressed recombination.
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Research Interests: Engineering, Materials Science, Nanoparticles, Advanced Materials, Medicine, and 15 moreOptoelectronics, Quantum Dots, Solar Energy, Semiconductor, Lead, Physical sciences, CHEMICAL SCIENCES, Bismuth, Particle Size, Quantum Dot, Advanced, Materials Testing, Quantum Dot Solar Cell, Nanocrystal, and Heterojunction
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The concept of a double-redox electrochemical capacitor operating in an aqueous electrolyte.
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Poster Presentation for the 2020 MRS Fall Meeting, November 28–December 4, 2020
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WP3 presentation Progress Meeting 14/07/21.
WP1 presentation 2nd annual meeting 13/09/2021
Electrochemical capacitors are attractive power sources, especially when they are able to operate at high frequency (high current regime). In order to meet this requirement their constituents should be made of high conductivity materials... more
Electrochemical capacitors are attractive power sources, especially when they are able to operate at high frequency (high current regime). In order to meet this requirement their constituents should be made of high conductivity materials with a suitable porosity. In this study, enhanced power and simultaneously high capacitance (120 F g − 1 at 1 Hz or 10 A g − 1) electrode material obtained from carbonized adenine precursor is presented. A micro/mesoporous character of the carbon with optimal pore size ratio and high surface area was proven by the physicochemical characterization. The beneficial pore structure and morphology resembling highly conductive carbon black, together with a significant nitrogen content (5.5%) allow for high frequency response of aqueous capacitor to be obtained. The carbon/carbon symmetric capacitor (in 1 mol L − 1 Li 2 SO 4) has been tested to the voltage of 1.5 V. The cyclic voltammetry indicates a good electrochemical response even at high scan rate (50 mV s − 1). The cyclability of the capacitor is comparable to the one operating with commercial carbon (YP50F). The adenine-based capacitor is especially favourable for stationary applications requiring high power.
Research Interests:
Electrochemical capacitors are attractive power sources, especially when they are able to operate at high frequency (high current regime). In order to meet this requirement their constituents should be made of high conductivity materials... more
Electrochemical capacitors are attractive power sources, especially when they are able to operate at high frequency (high current regime). In order to meet this requirement their constituents should be made of high conductivity materials with a suitable porosity. In this study, enhanced power and simultaneously high capacitance (120 F g − 1 at 1 Hz or 10 A g − 1) electrode material obtained from carbonized adenine precursor is presented. A micro/mesoporous character of the carbon with optimal pore size ratio and high surface area was proven by the physicochemical characterization. The beneficial pore structure and morphology resembling highly conductive carbon black, together with a significant nitrogen content (5.5%) allow for high frequency response of aqueous capacitor to be obtained. The carbon/carbon symmetric capacitor (in 1 mol L − 1 Li 2 SO 4) has been tested to the voltage of 1.5 V. The cyclic voltammetry indicates a good electrochemical response even at high scan rate (50 mV s − 1). The cyclability of the capacitor is comparable to the one operating with commercial carbon (YP50F). The adenine-based capacitor is especially favourable for stationary applications requiring high power.
Research Interests:
Electrochemical capacitors are attractive power sources, especially when they are able to operate at high frequency (high current regime). In order to meet this requirement their constituents should be made of high conductivity materials... more
Electrochemical capacitors are attractive power sources, especially when they are able to operate at high frequency (high current regime). In order to meet this requirement their constituents should be made of high conductivity materials with a suitable porosity. In this study, enhanced power and simultaneously high capacitance (120 F g − 1 at 1 Hz or 10 A g − 1) electrode material obtained from carbonized adenine precursor is presented. A micro/mesoporous character of the carbon with optimal pore size ratio and high surface area was proven by the physicochemical characterization. The beneficial pore structure and morphology resembling highly conductive carbon black, together with a significant nitrogen content (5.5%) allow for high frequency response of aqueous capacitor to be obtained. The carbon/carbon symmetric capacitor (in 1 mol L − 1 Li 2 SO 4) has been tested to the voltage of 1.5 V. The cyclic voltammetry indicates a good electrochemical response even at high scan rate (50 mV s − 1). The cyclability of the capacitor is comparable to the one operating with commercial carbon (YP50F). The adenine-based capacitor is especially favourable for stationary applications requiring high power.
Presentation at 1- XVIII Ciclo de conferencias Facultad de Ciencias "Divulgación por Diversión" 2- Curso Introducción á Nanociencia e a Nanotecnoloxía 21/22 A Coruña, 29 October 2021
Presentation at "Tecnociencia y Energía" Lyon, 16 October 2021
Minutes of the 2nd annual meeting 2021
WP3 presentation Progress Meeting 21/04/21
Optimized composition and preparation methods of nanostructured layered sulfide/carbon composites
WP3 presentation Progress Meeting 03/02/21
WP3 presentation Progress Meeting 16/11/20.
Kick-off meeting NOEL-WP1 and Presentation
WP3 presentation. 1st annual meeting 10/09/2020
WP1 presentation. Meeting 03/02/2021
WP1 presentation. Meeting 14/07/2021
WP1 presentation. 1st annual meeting (10/09/2020)
WP1 presentation. Meeting 16/11/2020
NOEL 1st annual meeting agenda
Poster Presentation for the 2020 MRS Fall Meeting, November 28–December 4, 2020
1st generation of nanomaterials (NC or NW) for energy storage applications
NOEL project website
Milestone 4: Well-characterized and reproducible nanostructured layered sulfide/carbon composites
Milestone 1 - Consortium Agreement signature