A5087017896- Silicon Nanostructures and Photoluminescence
- Semiconductor materials and devices
- Nanowire Synthesis and Applications
- Thin-Film Transistor Technologies
- Advanced Memory and Neural Computing
- Semiconductor materials and interfaces
- ZnO doping and properties
- Luminescence Properties of Advanced Materials
- Ga2O3 and related materials
- Silicon and Solar Cell Technologies
- Silicon Carbide Semiconductor Technologies
- Quantum Dots Synthesis And Properties
- Ferroelectric and Negative Capacitance Devices
- Copper-based nanomaterials and applications
- Ion-surface interactions and analysis
- Electronic and Structural Properties of Oxides
- Organic Light-Emitting Diodes Research
- Neuroscience and Neural Engineering
- Solid State Laser Technologies
- Gas Sensing Nanomaterials and Sensors
- Near-Field Optical Microscopy
- Conducting polymers and applications
- Chalcogenide Semiconductor Thin Films
- Dendrimers and Hyperbranched Polymers
- High-pressure geophysics and materials
Universitat de Barcelona
2015-2024
Institut de Nanociència i Nanotecnologia de la Universitat de Barcelona
2020-2023
University of Freiburg
2017-2020
Microsystems (United Kingdom)
2020
FC Barcelona
2019
Centre National de la Recherche Scientifique
2018-2019
Centre de Recherche sur les Ions, les Matériaux et la Photonique
2018-2019
École Nationale Supérieure d'Ingénieurs de Caen
2018-2019
Université de Caen Normandie
2018-2019
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2018-2019
Antimony trisulfide (Sb2S3), found in nature as the mineral stibnite, has been studied under compression at room temperature from a joint experimental and theoretical perspective. X-ray diffraction Raman scattering measurements are complemented with ab initio total-energy, lattice-dynamics, electronic structure calculations. The continuous changes observed volume, lattice parameters, axial ratios, bond lengths, mode frequencies function of pressure can be attributed to different...
Inkjet-printed h-BN memristors exhibit multiple stochastic phenomena that are very attractive for use as entropy sources in electronic circuits data encryption. The high variability can be exploited to create unique and unpredictable patterns.
Atomic layer-deposited (ALD) TiO2 thin films on silicon were deposited using titanium tetrachloride (TiCl4), tetraisopropoxide (TTIP), and tetrakis(dimethylamino)titanium (TDMAT) together with water vapor as the oxidant at temperatures ranging between 75 250 °C. The Si surface passivation quality of as-deposited isothermally annealed samples was compared photoconductance lifetime measurements in order to calculate their effective recombination velocities Seff. A low Seff 3.9 cm/s...
The soaring global demand for flexible, wearable and transparent devices has created an urgent need new fabrication technologies that are both cost-competitive eco-friendly.
Superlattices of Si-rich silicon nitride and Si3N4 are prepared by plasma-enhanced chemical vapor deposition and, subsequently, annealed at 1150 °C to form size-controlled Si nanocrystals (Si NCs) embedded in amorphous Si3N4. Despite well defined structural properties, photoluminescence spectroscopy (PL) reveals inconsistencies with the typically applied model quantum confined excitons nitride-embedded NCs. Time-resolved PL measurements demonstrate 105 times faster time-constants than...
Abstract Transparent Conducting Oxides (TCOs) are an enticing family of optoelectronic materials which have been proven to increase efficiency when incorporated into perovskite light emitting diode (PE‐LED) and organic OLED architectures as transport layers. Solution‐processed metal oxide inks already demonstrated, although there is still a need for high‐quality inkjet‐printable with thermal post‐process below 200 °C. The set in this work adapted from low‐boiling point colloidal suspensions...
We use Raman scattering to investigate the size distribution, built-in strains and crystalline degree of Si-nanoclusters (Si-nc) in high-quality Si-rich oxynitride/SiO2 multilayered samples obtained by plasma enhanced chemical vapor deposition subsequent annealing at 1150 °C. An initial structural characterization was performed means energy-filtered transmission electron microscopy (EFTEM) X-ray diffraction (XRD) obtain information about cluster presence significant amounts phase. The...
Abstract Phosphorus doping of silicon nanostructures is a non-trivial task due to problems with confinement, self-purification and statistics small numbers. Although P-atoms incorporated in Si influence their optical electrical properties, the existence free majority carriers, as required control electronic controversial. Here, we correlate structural, results size-controlled, P-incorporating nanocrystals simulation data address role interstitial substitutional P-atoms. Whereas atom probe...
Superlattices of Si3N4 and Si-rich silicon nitride thin layers with varying thickness were prepared by plasma enhanced chemical vapor deposition. After high temperature annealing, Si nanocrystals formed in the former layers. The control quantum dots size via SiNx layer was confirmed transmission electron microscopy. well agreement respective In addition X-ray diffraction evidenced that are crystalline whereas matrix remains amorphous even after annealing at 1200 °C. Despite proven formation...
Abstract Boron (B) doping of silicon nanocrystals requires the incorporation a B-atom on lattice site quantum dot and its ionization at room temperature. In case successful B-doping majority carriers (holes) should quench photoluminescence Si via non-radiative Auger recombination. addition, holes allow for non-transient electrical current. However, bottom end nanoscale, both substitutional are subject to significant increase in their respective energies due confinement size effects....
Charge transport and electroluminescence mechanisms in Si-rich Si oxynitride/silicon oxide (SRON/SiO2) superlattices deposited on p-type substrate are reported. The superlattice structures were by plasma-enhanced chemical-vapor deposition subsequently annealed at 1150 °C to precipitate crystallize the excess into nanocrystals. dependence of electrical conduction applied voltage temperature was found be well described a Poole-Frenkel mechanism over wide range. On other hand, observed SRON...
The effect of the annealing temperature and SiO2 barrier thickness silicon nanocrystal (NC)/SiO2 superlattices (SLs) on their structural optical properties is investigated. Energy-filtered transmission electron microscopy (TEM) revealed that SL structure maintained for temperatures up to 1150 °C, with no variation nanostructure morphology different thicknesses. Nevertheless, as high 1250 °C promote diffusion Si atoms into layers, which produces larger NCs loss NC size control expected from...
By using ZnO thin films doped with Ce, Tb or Eu, deposited via radiofrequency magnetron sputtering, we have developed monochromatic (blue, green and red, respectively) light emitting devices (LEDs). The rare earth ions introduced doping rates lower than 2% exhibit narrow intense emission peaks due to electronic transitions in relaxation processes induced after electrical excitation. This study proves zinc oxide be a good host for these elements, its high conductivity optical transparency the...
A novel approach to disentangle the electronic features corresponding pure Si-NCs from their surrounding dielectric material.
Low-power, high-performance metal–insulator–metal (MIM) non-volatile resistive memories based on HfO2 high-k dielectric are fabricated using a drop-on-demand inkjet printing technique as low-cost and eco-friendly method. The characteristics of switching Pt (bottom)/HfO2/Ag (top) stacks Si/SiO2 substrates investigated in order to study the bottom electrode's interaction with layer resulting effects switching. devices show low Set Reset voltages, high ON/OFF current ratio, relatively (∼1 μA),...
The optical, electrical and electro-optical properties of metal-insulator-semiconductor (MIS) devices containing Si-rich silicon nitride (SRN) films are reported. photoluminescence optical absorption characterization evidences that optically active centers present a defective nature. As consequence, Poole-Frenkel type transport mechanism is considered, which in agreement with the results. performance has been found to be strongly modulated by poly-Si electrode transmittance. After taking...
Stable interfacial contact in p–n CuO–ZnO nanostructures with different morphologies synthesized <italic>via situ</italic> addition of a controlled copper remarkably improved their photocatalytic properties contrast to incorporation by an impregnation approach.
We offer a complete structural and optical study of samples containing silicon nanocrystals (Si-NCs) embedded in SiO2/SiON multilayers, varying the oxynitride layer thickness from 2.5 to 7 nm. Using energy-filtered transmission electron microscopy we have determined size distribution precipitated Si-nanoaggregates. Raman scattering measurements were used investigate Si-NC crystalline quality. By combining both techniques, nanoaggregate degree has been evaluated, with values around 50% for...
The effect of the oxide barrier thickness (tSiO2) reduction and Si excess ([Si]exc) increase on electrical electroluminescence (EL) properties Si-rich oxynitride (SRON)/SiO2 superlattices (SLs) is investigated. active layers metal–oxide–semiconductor devices were fabricated by alternated deposition SRON SiO2 top a substrate. precipitation thus formation nanocrystals (NCs) within was achieved after an annealing treatment at 1150 °C. A structural characterization revealed high crystalline...
Silicon nanocrystals (Si NCs) embedded in Si-based dielectrics provide a high band gap material (1.7 eV) and enable the construction of all-crystalline Si tandem solar cells. However, nanocrystal formation involves high-temperature annealing which deteriorates properties any previously established selective contacts. The inter-diffusion dopants during alters NC limits built-in voltage. Furthermore, most devices presented so far also involve electrically active bulk therefore do not allow...
The resistive switching properties of ITO/ZnO/p-Si devices have been studied, which present well-defined resistance states with more than five orders magnitude difference in current. Both the high state (HRS) and low (LRS) were induced by either sweeping or pulsing voltage, observing some differences HRS. Finally, charge transport mechanisms dominating pristine, HRS, LRS analyzed depth, obtained structural parameters suggest a partial re-oxidation conductive nanofilaments reduction effective area.