A5053872241- Electronic and Structural Properties of Oxides
- Ferroelectric and Piezoelectric Materials
- Semiconductor materials and devices
- Catalysis and Oxidation Reactions
- ZnO doping and properties
- Machine Learning in Materials Science
- Advanced Photocatalysis Techniques
- Surface and Thin Film Phenomena
- Multiferroics and related materials
- Electron and X-Ray Spectroscopy Techniques
- Gas Sensing Nanomaterials and Sensors
- Phosphorus and nutrient management
- Magnetic properties of thin films
- Magnetic and transport properties of perovskites and related materials
- Copper-based nanomaterials and applications
- Thermochemical Biomass Conversion Processes
- Advanced Chemical Physics Studies
- Carbon and Quantum Dots Applications
- Ga2O3 and related materials
- Microwave Dielectric Ceramics Synthesis
- Atomic and Subatomic Physics Research
- Electrophoretic Deposition in Materials Science
- Perovskite Materials and Applications
- Solid-state spectroscopy and crystallography
- Conducting polymers and applications
National Institute of Materials Physics
2015-2024
University of Bucharest
2016-2018
We monitored the evolution in time of pinhole-free structures based on FTO/TiO2/CH3NH3PbI2.6Cl0.4 layers, with and without spiro-OMeTAD counter electrodes (Ag, Mo/Ag, Au), aged at 24 °C a dark nitrogen atmosphere. In absence electrodes, no degradation occurs. While devices Au show only 10% drop power conversion efficiency, remaining stable after further overheating 70 °C, >90% is lost when using Ag, process being slower for Mo/Ag. demonstrate that iodine dislocated by electric field between...
Abstract The process of N‐doping is frequently employed to enhance the properties carbon quantum dots. However, precise requirements for nitrogen precursors in producing high‐quality N‐doped dots (NCQDs) remain undefined. This research systematically examines influence various dopants on morphology, optical features, and band structure NCQDs. are synthesized using an efficient, eco‐ friendly, rapid continuous hydrothermal flow technique. method offers unparalleled control over synthesis...
Willows from engineered wetland systems (EWS) offer a sustainable approach to wastewater treatment and biomass production. Our study assesses their potential for nutrient recovery carbon sequestration using slow pyrolysis (600 °C) hydrothermal carbonization (250 °C). Here, we propose EWS-pyrochars as ready-tointegrate opportunity soil amendment, they exhibit predominant CO2 release the absence of harmful compounds in pyrolysis-chromatograms, indicating higher stability than hydrocars. Using...
The compensation of the depolarization field in ferroelectric layers requires presence a suitable amount charges able to follow any variation polarization. These can be free carriers or charged defects located material coming from electrodes. Here we show that self-doping phenomenon occurs epitaxial, tetragonal films Pb(Zr0.2Ti0.8)O3, consisting generation point (vacancies) acting as donors/acceptors. are introducing partly compensate occurring film. It is found concentration introduced by...
The orientation of polarization in ferroelectric thin films is important for applications these materials nonvolatile memory and field-effect transistors with gates, catalysis photocatalysis. One means control to choose a well defined substrate, but the influence substrate's electronic properties on not understood. In this investigation model systems, experimental findings are integrated electrostatic models determine magnitudes orientations interfacial electric fields that useful setting epilayer.
Carbon monoxide is reversibly adsorbed and desorbed on (001) barium titanate, with adsorption processes controlled by the ferroelectric state of substrate. This finding suggests that titanate suitable for carbon sequestration.
Abstract Atomically clean lead zirco-titanate PbZr 0.2 Ti 0.8 O 3 (001) layers exhibit a polarization oriented inwards P (−) , visible by band bending of all core levels towards lower binding energies, whereas as introduced (+) under air or in ultrahigh vacuum. The magnitude the decreases when temperature is increased at 700 K. CO adsorption on polarized surfaces saturates about one quarter monolayer carbon, and occurs both molecular (oxidized) dissociated (reduced) states with large...
Irradiating ferroelectric Pb(Zr,Ti)O<sub>3</sub> surfaces with soft X-rays promotes a higher efficiency dissociation of areas without out-of-plane polarization.
Abstract The development of robust, safe, cost‐effective and efficient photocatalytic systems for water splitting should take into account the presence a proper powerful photon absorber an efficient, low‐cost earth‐abundant electrocatalyst to perform reaction at high conversions. In this study, Ni−Zn/TiO 2 ternary composites with activity under UV irradiation were successfully prepared via simple deposition‐precipitation route. Thus, different Ni : Zn molar ratios (1 0, 1 1, 3 6 9 0 1)...
Probing of the free surface ferroelectric properties thin polar films can be achieved either by estimating band bending variance under top-most layer or studying extent extrinsic charge accumulated outside surface. Photoemitted incoming low-energy electrons used to characterize locally both in a spectromicroscopic approach. Thin lead zirco-titanate (PZT) is investigated combining low energy/mirror electron microscopy (LEEM/MEM) with photoemission (PEEM) and high-resolution photoelectron...
This contribution is a review of recent aspects connected with photoelectron spectroscopy free ferroelectric surfaces, metals interfaced these graphene-like layers together some exemplifications concerning molecular adsorption, dissociations and desorptions occurring from ferroelectrics. Standard used nowadays in correlation other characterization techniques, such as piezoresponse force microscopy, high resolution transmission electron spectroscopy, hysteresis cycles. In this work we will...
The effects of Li addition on the luminescence Ln–SnO<sub>2</sub> depend Ln type, which are classified as surface (Dy, Tb) and substitutional dopants (Eu, Sm, Er).
Willows from engineered wetland systems (EWS) offer a sustainable approach to wastewater treatment and biomass production. Our study assesses their potential for nutrient recovery carbon sequestration using slow pyrolysis (600 °C) hydrothermal carbonization (250 °C). Here, we propose EWS-pyrochars as ready-to-integrate opportunity soil amendment, they exhibit predominant CO2 release the absence of harmful compounds in pyrolysis-chromatograms, indicating higher stability than hydrocars. Using...
Photoelectron spectromicroscopy data cubes with sub-micrometer spatial resolution from a lead zirconate titanate thin film are fitted in each point for several areas investigated, and correlations between the results of fitting parameters established, enabling one to suggest that surface band bending manifests also case samples multiple polarization states. These bendings may be used preliminary assessment states by using contrast binding energy. However, individual curve spectrum analysis...
Photoelectron spectromicroscopy data cubes with sub-micrometer spatial resolution from a lead zirconate titanate thin film are fitted in each point for several areas investigated, and correlations between the results of fitting parameters established, enabling one to sugges that surface band bending manifests also case samples multiple polarization states. These bendings may be used preliminary assessment states by using contrast binding energy. However, individual curve spectrum analysis...
Photoelectron spectromicroscopy data cubes with sub-micrometer spatial resolution from a lead zirconate titanate thin film are fitted in each point for several areas investigated, and correlations between the results of fitting parameters established, enabling one to prove that surface band bending manifests also case samples multiple polarization states. These bendings may be used preliminary assessment states by using contrast binding energy. However, individual curve spectrum analysis...