A5012148705- Semiconductor materials and devices
- Semiconductor materials and interfaces
- Electronic and Structural Properties of Oxides
- Thin-Film Transistor Technologies
- Nanowire Synthesis and Applications
- Organic Electronics and Photovoltaics
- Silicon Nanostructures and Photoluminescence
- Integrated Circuits and Semiconductor Failure Analysis
- Organic Light-Emitting Diodes Research
- Ga2O3 and related materials
- Advancements in Semiconductor Devices and Circuit Design
- Electron and X-Ray Spectroscopy Techniques
- TiO2 Photocatalysis and Solar Cells
- Surface and Thin Film Phenomena
- Advanced Memory and Neural Computing
- Advanced Photocatalysis Techniques
- GaN-based semiconductor devices and materials
- Silicon and Solar Cell Technologies
- Quantum Dots Synthesis And Properties
- Perovskite Materials and Applications
- Anodic Oxide Films and Nanostructures
- ZnO doping and properties
- Advanced Sensor and Energy Harvesting Materials
- Ferroelectric and Piezoelectric Materials
University of Patras
2013-2022
National Centre of Scientific Research "Demokritos"
2016-2020
The reduction in electronic recombination losses by the passivation of surfaces is a key factor enabling high‐efficiency solar cells. Here strategy to passivate surface trap states TiO 2 films used as cathode interlayers organic photovoltaics (OPVs) through applying alumina (Al O 3 ) or zirconia (ZrO insulating nanolayers thermal atomic layer deposition (ALD) investigated. results suggest that traps are oxygen vacancies, which cause undesirable and high electron extraction barrier, reducing...
Atomic layer deposition of HfO<sub>2</sub> significantly increases the efficiency and prolongs lifetime organic solar cells.
High capacitance density three-dimensional (3D) metal-insulator-semiconductor (MIS) capacitors using Si nanowires (SiNWs) by metal-assisted chemical etching and atomic-layer-deposited alumina dielectric film were fabricated electrically characterized. A treatment was used to remove structural defects from the nanowire surface, in order reduce of interface traps at Al2O3/SiNW interface. SiNWs with two different lengths, namely, 1.3 μm 2.4 μm, studied. four-fold increase compared a planar...
Si nanowires (SiNWs) produced by metal-assisted chemical etching on n-type were investigated for their use as a light-trapping material in c-Si solar cells. The fabricated before junction formation (on lightly doped substrate) so that core was bulk and nonporous. above fabrication process implemented cell fabrication. SiNW reflectivity tested at different steps of processing found to be lower than conventional random pyramids used Contact the front side considering metal deposition either...
The influence of interfacial oxidized Ge layer, inadvertently grown during ALD Al2O3 films, on the properties Al2O3/p-Ge MOS structures is studied. Keeping constant deposition temperature at 300°C, it shown that thickness layer increases from ∼0.2 to ∼0.5 nm, as 5 10 maintaining a composition either mixed Ge4+/Ge3+ oxide or GeAlOx germanate. However, for 25 nm decreases below 0.1 nm. density interface traps shows strong dependence regardless thickness.
Metal oxide semiconductor capacitors that incorporate tantalum pentoxide (Ta2O5) thin films as dielectric were fabricated via the atomic layer deposition (ALD) technique and characterized through TEM, XPS, C–V, I–V measurements. TEM analysis revealed amorphous phase of Ta2O5 existence an ultrathin SiOx in Ta2O5/p-Si interface, also evidenced by XPS spectra. verified stoichiometry ALD-deposited films. Furthermore, results indicate values 2.5 0.7 eV for conduction valence band offsets...
Zirconium oxide (ZrO2) thin films of 5 and 25 nm thickness were deposited by atomic layer deposition at 250 °C on p-type Ge substrates. The stoichiometry, thickness, valence band electronic structure the ZrO2 investigated x-ray ultraviolet photoelectron spectroscopies. For electrical characterization, metal-oxide-semiconductor (MOS) capacitive structures (Pt/ZrO2/p-Ge) have been fabricated. Capacitance–voltage conductance–voltage (C–V, G–V) measurements performed ac impedance spectroscopy in...
Polymer solar cells have attracted tremendous interest in the highly competitive energy sector, due to practical advantages they exhibit, such as being lightweight, flexible, and low cost, stark contrast traditional photovoltaic technologies. However, their successful commercialization is still hindered by issues related device instability. Here, atomic layer deposition (ALD) employed deposit conformal ultrathin dielectrics, alumina (Al 2 O 3 ) zirconia (ZrO ), on top of ZnO electron...
The influence of deposition temperature on the structural, chemical, and electrical properties atomic layer (ALD)-Al2O3 thin films is investigated. ALD-Al2O3 were deposited p-type Ge substrates at 80, 150, 200, 250, 300 °C. force microscopy analysis reveals smooth cohesive with extremely low roughness (0.2–0.6) nm On contrary, Al2O3 lowest available (80 °C) exhibit holes aggregates implying a nonhomogeneous deposition. x-ray photoelectron spectroscopy (XPS) indicates presence stoichiometric...
Abstract The electrical behaviour of Al/Al 2 O 3 /p‐Ge MOS capacitors, with 10 nm oxide thickness, has been studied in the temperature range between 130 K and 330 K. ALD method for Al deposition used. C‐V G‐f measurements reveal high values density interfacial traps D it , suggesting presence leakage currents. Conductivity mechanisms currents have studied, on basis J‐V characteristics structure as a function temperature. In measured voltage region (0‐2.5 V), tunneling is proposed dominant...
It is well known that the most critical issue in Ge CMOS technology successful growth of high-k gate dielectrics on substrates. The high interface quality Ge/high-k dielectric connected with advanced electrical responses based MOS devices. Following this trend, atomic layer deposition deposited ultrathin Al2O3 and HfO2 films were grown p-Ge. acts as a passivation between p-Ge films. An extensive set p-Ge/Al2O3/HfO2 structures fabricated thickness ranging from 0.5 nm to 1.5 varying 2.0 3.0...
Abstract Metal–insulator–metal (MIM) micro-capacitors for use in integrated energy storage applications are presented. A new, simple and batch Si processing compatible method the creation of high aspect ratio metallic 3D structures on surface a substrate is described. The consists creating an array nanopillars then depositing Al at small angle off vertical while rotating sample. Using this method, effective area samples increased by factor 3.8. Various capacitors created using described as...
Abstract The knowledge of the electronic structure interface is important when designing microelectronic devices with maximum efficiency, based on oxide heterostructures. design tends to utilize thinner layers materials in order reduce their overall volume and maximize resulting up a few nanometers. Incorporation sub-nanometer oxides onto surfaces often used improve efficiency polymer solar cells. In this work, chemical composition valence band interfaces formed by ultra-thin, less than 1...