A5071757484- Chalcogenide Semiconductor Thin Films
- Quantum Dots Synthesis And Properties
- Copper-based nanomaterials and applications
- Semiconductor materials and interfaces
- Phase-change materials and chalcogenides
- Crystal Structures and Properties
- Machine Learning in Materials Science
- Perovskite Materials and Applications
- Advanced Thermoelectric Materials and Devices
- Gas Sensing Nanomaterials and Sensors
- ZnO doping and properties
- Metal Extraction and Bioleaching
- Solid-state spectroscopy and crystallography
- Thin-Film Transistor Technologies
- Advanced Semiconductor Detectors and Materials
- Water Quality Monitoring and Analysis
- Optical properties and cooling technologies in crystalline materials
- Nanoparticles: synthesis and applications
- Supercapacitor Materials and Fabrication
- Advancements in Battery Materials
- Advanced Battery Materials and Technologies
- Advanced battery technologies research
- Mineralogy and Gemology Studies
- Semiconductor materials and devices
- Advanced Nanomaterials in Catalysis
Institut de Recerca en Energia de Catalunya
2016-2025
University of Luxembourg
2023
Martin Luther University Halle-Wittenberg
2022
Universitat Politècnica de Catalunya
2022
Universitat de Barcelona
2022
Academy of Sciences of Moldova
2012-2021
Institute of Applied Physics
2012-2021
Lappeenranta-Lahti University of Technology
2016-2018
Abstract The efficiency of kesterite-based solar cells is limited by various non-ideal recombination paths, amongst others a high density defect states and the presence binary or ternary secondary phases within absorber layer. Pronounced compositional variations phase segregation are indeed typical features non-stoichiometric kesterite materials. Certainly thin film with an off-stoichiometric layer composition, especially Cu-poor/Zn-rich, achieved highest efficiencies, but deviations from...
Abstract A non-destructive Raman spectroscopy has been widely used as a complimentary method to X-ray diffraction characterization of Cu 2 ZnSnS 4 (CZTS) thin films, yet our knowledge the active fundamental modes in this material is far from complete. Focusing on polarized provides important information about relationship between and CZTS crystal structure. In framework zone–center optical phonons CZTS, which most usually examined layers based solar cells, are studied by resonant...
This work presents a complete analysis of Raman active modes Sb2Se3 measured by six different excitation wavelengths from NIR to UV, under polarization configurations and at low temperature.Simultaneous fitting spectra allowed the deconvolution identification 28 peaks obtained in monocrystalline sample 30 predicted group theory for this crystalline structure.Analysis yielded preliminary assignment symmetry, while measurements temperature resulted fine resolution spectra.Additionally,...
UV-based resonant Raman spectroscopy is an effective technique for a non-destructive assessment of defects in kesterite materials.
Example of an advanced characterization study a complex system (thin film solar cell) that may serve as instructive handbook to help building up the full picture multilayer-based devices for broad spectrum readers and researchers.
Abstract A major challenge in thermoelectrics (TEs) is developing devices made of sustainable, abundant, and non‐toxic materials. Furthermore, the technological drive toward low sizes makes crucial study nano micro configurations. In this work, thin film TE based on p‐type Cu 2+ x Zn 1‐ SnS 4 SnSe , n‐type Al y O are fabricated by physical vapor deposition. The kesterite phases show good purity promising power factor, likely enhanced copper–zinc order–disorder transition. Thin generators...
The polarized Raman spectra of the Cu2ZnSnSe4 and Cu2ZnGeSe4 single crystals were measured for various in-plane rotation angles on basal (1 1 2) crystal facet. position up to 15 (for Cu2ZnSnSe4) 16 Cu2ZnGeSe4) peaks was determined in spectral region 50–300 cm−1. From analysis experimental dependence intensity with angle, a symmetry assignment most detected modes an estimation numerical values tensor elements derived. kesterite type structure established by quantity observed nonpolar A polar...
Six different thin film solar cells consisting of either orthorhombic (α-SnS) or cubic (π-SnS) tin(ii) sulfide absorber layers have been fabricated, characterized and evaluated. Absorber π-SnS α-SnS were selectively deposited by temperature controlled Aerosol Assisted Chemical Vapor Deposition (AA-CVD) from a single source precursor. grown on molybdenum (Mo), Fluorine-doped Tin Oxide (FTO), FTO coated with amorphous-TiO x layer (am-TiO -FTO), which shown to significant impact the growth rate...
Temperature induced Cu<sub>2</sub>SnS<sub>3</sub>phase transition from a defective cubic to monoclinic structure assessed by Raman spectroscopy and leading higher photovoltaic efficiency.
High nonradiative recombination, low diffusion length and band tailing are often associated with a large open circuit voltage deficit, which results in efficiency of Cu2ZnSnS4 (CZTS) solar cells. Recently, cation substitution CZTS has gained interest as plausible solution to suppress these issues. However, the common substitutes, Ag Cd, not ideal due their scarcity toxicity. Other transition-metal candidates (e.g., Mn, Fe, Co, or Ni) multivalent, may form harmful deep-level defects....
The beneficial effect of Ge doping on kesterite absorbers is revealed and insights into kesterite's intrinsic defect chemistry are given.
Fabrication on transparent soda-lime glass/fluorine-doped tin oxide (FTO) substrates opens the way to advanced applications for kesterite solar cells such as semitransparent, bifacial, and tandem devices, which are key future of PV market. However, complex behavior p-kesterite/n-FTO back-interface potentially limits power conversion efficiency devices. Overcoming this issue requires careful interface engineering. This work empirically explores use transition-metal oxides (TMOs) Mo-based...
In this study, ZnO/Ag nanocomposites were synthesized using a facile chemical route involving metallic precursors of zinc acetate dehydrate and silver acetate, dissolving the two in EtOH. The final concentration solution was 0.4 M. different atomic percentages to compare amount nanoparticles with bactericidal power nanocomposites. They prepared at concentrations 0, 1, 3, 5, 7, 10 at%. as-prepared characterized X-ray diffraction (XRD), scanning electron microscopy (SEM) transmission (STEM)...
Recently, the interest for family of low dimensional materials has increased significantly due to anisotropic nature their fundamental properties. Among them, antimony sulfide (Sb
This work showcases the importance of developing suitable inspection and analysis methodologies with high statistical relevance data coupled machine learning algorithms, for detection, control, understanding small fluctuations in scale-up thin film photovoltaics to industrial sizes. To exhibit this methodology, investigates effect subtle inhomogeneities on efficiency solar cells based Cu2ZnSnSe4/CdS interface using two large area samples subdivided ≈400 individual cells. A dataset obtained...
The polarized Raman spectra of the Cu2ZnSiS4 and Cu2ZnSiSe4 single crystals were investigated as a function in-plane rotation angle on basal (210) crystal planes. position up to 32 (for sulphide compound) 27 selenide peaks was determined for each compounds in spectral region 50–600 cm−1. A careful analysis high resolution that measured under different polarization configurations has allowed determining A1(TO), A2, B1/B2(TO + LO) symmetry dominant some weaker modes. investigation dependence...
High performance kesterite (CZTSe) based solar cell devices usually employ an absorber/buffer heterostructure using toxic CdS deposited by chemical bath deposition (CBD) as buffer layer.This is due to the favourable spike like conduction band alignment of and CZTSe absorber.ZnS(O,OH) layers provide a promising nontoxic alternative.Here, variation thiourea concentration in CBD ZnS(O,OH) its influence on device performances pure selenide cells presented.Furthermore, layer conditions light...
A comprehensive vibrational analysis of the kesterite Cu<sub>2</sub>ZnGeS<sub>4</sub>is reported, which includes in-plane rotation polarized Raman scattering measurements from (1 0 1)-single crystal facet as well first principle lattice dynamic calculations.
Accurate anionic control during the formation of chalcogenide solid solutions is fundamental for tuning physicochemical properties this class materials. Compositional grading key aspect band gap engineering and especially valuable at device interfaces an optimum alignment, controlling interface defects recombination optimizing carrier-selective contacts. However, a simple reliable technique that allows standardizing compositional profiles currently missing kesterites feasibility achieving...
The experimental resonant and non-resonant Raman scattering spectra of the kesterite structural modification Cu2ZnGeS4 single crystals are reported. results compared with those calculated theoretically within density functional perturbation theory. For majority lines a good agreement (within 2-5 cm(-1)) is established between mode frequencies. However, several dominant spectral lines, in particular two intense fully symmetric modes, found to deviate from values by as much 20 cm(-1). A...