A5108831194- Semiconductor materials and devices
- Semiconductor materials and interfaces
- Ferroelectric and Negative Capacitance Devices
- Silicon and Solar Cell Technologies
- Silicon Nanostructures and Photoluminescence
- GaN-based semiconductor devices and materials
- Copper Interconnects and Reliability
- Ga2O3 and related materials
- Geochemistry and Geologic Mapping
- Advancements in Semiconductor Devices and Circuit Design
- Recycling and Waste Management Techniques
- Luminescence Properties of Advanced Materials
- Thin-Film Transistor Technologies
- Electronic and Structural Properties of Oxides
- Advanced Memory and Neural Computing
- Industrial Vision Systems and Defect Detection
- Integrated Circuits and Semiconductor Failure Analysis
- Quantum Dots Synthesis And Properties
- Laser-induced spectroscopy and plasma
- Analytical chemistry methods development
- Nanowire Synthesis and Applications
- Photonic and Optical Devices
- Silicon Carbide Semiconductor Technologies
- Extraction and Separation Processes
- Glass properties and applications
TU Bergakademie Freiberg
2016-2025
Schott (Germany)
2023-2024
Fraunhofer Institute for Integrated Systems and Device Technology
2023-2024
Institute of Applied Physics
2024
Fraunhofer Institute for Photonic Microsystems
2023
GlobalFoundries (Germany)
2023
Technologiezentrum Halbleitermaterialien
2022
NaMLab (Germany)
2010-2011
Max Planck Institute of Microstructure Physics
2002-2006
Infineon Technologies (United Kingdom)
2006
A detailed analysis of the strong room-temperature photoluminescence (PL) signal size controlled nc-Si is reported. The control realized by evaporation ${\mathrm{S}\mathrm{i}\mathrm{O}/\mathrm{S}\mathrm{i}\mathrm{O}}_{2}$ superlattices and subsequent thermally induced phase separation. By this method synthesis completely ${\mathrm{SiO}}_{2}$ passivated Si nanocrystals with a demonstrated. blueshift from 1.3 to 1.65 eV decreasing crystal observed. Resonant measurements prove breakdown...
A new degradation mechanism (LeTID, Light and elevated Temperature Induced Degradation) for multicrystalline solar cells is presented. The reaches relative power losses of up to 10% on a time scale several hundreds hours carrier injection at field relevant temperatures. LeTID leads highly dependent lifetime characteristic after features regeneration phase. Characteristics as function temperature level are presented comparison between laboratory outdoor tests drawn. significantly reduced by...
In this work the carrier lifetime evolution of different passivation layers under illumination and at elevated temperatures are investigated. Multicrystalline silicon samples were treated by implementing typical industrial processing steps. The degradation was found to depend strongly on surface type, but is independent doping oxide charge. influence layer bulk After reaching a maximum, feature regeneration phase. Capacitance-voltage measurements show that charge not influenced degradation,...
If not adequately suppressed, Light and elevated Temperature Induced Degradation (LeTID) has been shown to cause severe degradation of multicrystalline (mc-Si) silicon solar cells modules with passivated emitter rear cell (PERC). Within this work, the system performance LeTID-sensitive mc-Si is investigated when operated in temperate mediterranean climates, a correlation predict observed field based on accelerated laboratory testing presented. Severe induced by LeTID up 7% maximum output...
Polymers represent around 25% of total waste from electronic and electric equipment. Any successful recycling process must ensure that polymer-specific functionalities are preserved, to avoid downcycling. This requires a precise characterization particle compounds moving at high speeds on conveyor belts in processing plants. We present an investigation using imaging point measurement spectral sensors 23 polymers including ABS, PS, PC, PE-types, PP, PVC, PET-types, PMMA, PTFE assess their...
High-k dielectric layers (HfSixOy and ZrO2) with different film morphologies were investigated by tunneling atomic-force microscopy (TUNA). Different current distributions observed for amorphous nanocrystalline films analyzing TUNA maps. This even holds crystalline where highly resolved cannot detect any structures. However, enables the determination of morphology in terms differences densities between grains their boundaries. The proven high-resolution transmission electron microscopy....
The lack of a dipolar second‐order susceptibility (χ (2) ) in silicon due to the centrosymmetry its diamond lattice usually inhibits efficient nonlinear optical processes bulk. Recently, deposition stressed nitride layers and corresponding inhomogeneous strain lead demonstration second harmonic generation electro‐optic modulation strained waveguides. However, respective impact stress/strain gradient involved interfaces is not clear. Here, influence stress stressing layer using measurements...
Highly insulating layers are a prerequisite for gallium nitride (GaN)‐based power electronic devices. For this purpose, carbon doping is one of the currently pursued approaches. However, its impact on optical and electrical properties GaN has been widely debated in scientific community. further improvement device performance, better understanding role related defects essential. To study optically active point defects, photoluminescence most frequently used experimental characterization...
Thin ZrO2 films are of high interest as high-k material in dynamic random access memory (DRAM), embedded memory, and resistive well for gate oxides. Actually, is predicted to be the key future DRAM generations below 20 nm. Profound knowledge pure doped thin films, especially structural properties, essential order meet requirements devices. This paper gives a detailed overview about properties dependence various process parameters. The study atomic layer deposition (ALD) growth mechanisms on...
The surface passivation performance of Al2O3 films attracted attention in the field solar cells and semiconductor devices depends on conditions applied post-deposition annealing step. effect temperature different atmospheres quality atomic layer deposited was investigated n-type float-zone Si wafers. Photoconductance decay measurements were carried out to characterize recombination velocities carrier lifetimes. chemical field-effect mechanism, i.e. interface trap density fixed charge...
The complex process of supercontinuum generation (SG) is known to be exploitable for designing spatially coherent white light sources emitting simultaneously in the ultraviolet, visible, and infrared ranges. Herein first natural material able generate laboratory conditions a similar those from man‐made photonic crystal fibers described. ability resides siliceous 20–50 cm long spicules glass sponge Sericolophus hawaiicus . By shedding into optical peak intensities ranging 1 100 TW −2 SG...
This article reports an improvement in the performance of hafnium oxide-based (HfO2) ferroelectric field-effect transistors (FeFET) achieved by a synergistic approach interfacial layer (IL) engineering and READ-voltage optimization. FeFET devices with silicon dioxide (SiO2) oxynitride (SiON) as IL were fabricated characterized. Although FeFETs SiO2 interfaces demonstrated better low-frequency characteristics compared to SiON interfaces, latter WRITE endurance retention. Finally, neuromorphic...
The light‐ and temperature‐induced degradation (LeTID) of Si‐based solar cells remains one their common stability issues. process affecting factors are still widely discussed. Low‐temperature photo‐ electroluminescence deep‐level transient spectroscopy (DLTS) rarely used in the LeTID studies. methods can explore only small‐area samples extracted from cells. A comparison fabricated initial, degraded, regenerated states by these is effective if for same location cell. mesa‐diodes various...
New energy, transport, computer and telecommunication technologies require an increasing supply of rare earth elements (REEs). As a consequence, adequate robust detection methods become essential for the exploration discovery new deposits, improved characterization existing deposits future recycling today’s high-tech products. Within this paper, we investigate potential combining passive reflectance (imaging point sampling) with laser stimulated luminescence (point spectroscopic measurements...
Growth conditions have a tremendous impact on the unintentional background impurity concentration in gallium nitride (GaN) synthesized by molecular beam epitaxy and its resulting chemical physical properties. In particular for oxygen identified as dominant we demonstrate that under optimized growth stoichiometry temperature is key parameter to control incorporation an increase 55 °C leads reduction one order of magnitude. Quantitatively this optical electrical properties are analyzed...
Abstract Carbon‐doping of GaN layers with thickness in the mm‐range is performed by hydride vapor phase epitaxy. Characterization optical and electrical measurements reveals semi‐insulating behavior a maximum specific resistivity 2 × 10 Ω cm at room temperature found for carbon concentration 8.8 18 −3 . For higher levels up to 3.5 19 , slight increase conductivity observed related self‐compensation passivation acceptor. The acceptor can be identified as C N an activation energy 0.94 eV...
Using photon-in photon-out soft x-ray spectroscopy, the electronic structure of silicon nanoclusters embedded in an electrically insulating SiO2 host matrix is investigated as a function nanocluster size. We find to be core-shell with crystalline Si core and thin transition layer suboxide. Effects quantum confinement are detected cores. that influence confined excitonic states manifests itself predominantly unoccupied states.
Atomic layer deposition-grown Al2O3 thin films are grown on n-type GaN and annealed at 300 or 500 °C in various atmospheres. Metal–insulator–semiconductor capacitors (MISCAPs) used as simplified test structures for AlGaN/GaN heterostructure field effect transistors with an gate dielectric. Electrical characterization of the unannealed MISCAPs reveals a low leakage current density ∼1.4 × 10−9 A/cm2 −2 MV/cm. Annealing N2 forming gas results degradation this level by more than one order...
The optical and persistent luminescence properties of CaB2O4:Ce3+ phosphor are presented. emission for excitation in the 250–340 nm wavelength region is dominated by two bands at 365 460 nm. Lifetime measurements suggested that band due to interconfigurational Ce3+ 5d → 4f transitions. Upon with a 254 UV lamp, superlong UVA1 (340–400 nm, blacklight) was observed, lasting least 15 h, excellent reproducibility, which perfectly suitable phototherapy application. initial-rise method applied on...