A5010433155- Silicon and Solar Cell Technologies
- Semiconductor materials and interfaces
- Thin-Film Transistor Technologies
- Silicon Nanostructures and Photoluminescence
- Integrated Circuits and Semiconductor Failure Analysis
- Electron and X-Ray Spectroscopy Techniques
- Advanced Surface Polishing Techniques
- Advancements in Semiconductor Devices and Circuit Design
- Magnetic Properties and Applications
- Nanowire Synthesis and Applications
- Semiconductor materials and devices
University of Freiburg
2019-2023
Fraunhofer Institute for Solar Energy Systems
2019-2023
Czochralski‐grown gallium‐doped silicon wafers are now a mainstream substrate for commercial passivated emitter and rear cell (PERC) devices allow retention of established processes while offering enhanced stability. We have assessed the carrier lifetime potential such in dependence resistivity, finding effective lifetimes well into millisecond region without any gettering or hydrogenation processing, thus demonstrating one advantage over boron‐doped silicon. Second, stability PERC cells...
One of the capabilities focused ion beam systems is milling. The purpose this work to explore capability as a tool for integrated circuit restructuring. Methods cutting and joining conductors are needed. Two methods demonstrated. first consists spinning nitrocellulose (a self-developing resist) on circuit, exposing an area, say, 7×7 μm, then milling smaller via with sloping sidewalls through metal layer down second, e-beam evaporating metal, dissolving achieve liftoff. resistance these links...
The response of lifetime samples made from boron‐ and gallium‐doped Czochralski‐grown silicon the same producer to light‐ elevated temperature‐induced degradation (LeTID) conditions (varying illumination at 75 °C), dark anneals (DAs) 175 °C, temporary recovery (TR) reaction under different is investigated. It found that Ga‐doped behave very differently than their B‐doped counterparts: while carrier remains a high level if an equivalent 1 sun °C applied, strong occurs low light intensities. A...
The recombination parameter <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">J</i> <sub xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> xmlns:xlink="http://www.w3.org/1999/xlink"><sub>s</sub></i> provides an important metric to characterize surface recombination. For its calculation, numerous methods and models have be applied. Since the for Auger radiative in crystalline silicon were recently revised, it is investigate influence of these...
In this work we present results of a series experiments to investigate the origin defects causing light and elevated temperature induced degradation (LeTID). It has been demonstrated that LeTID effects can be observed even in high purity monocrystalline silicon. The are therefore performed on float-zone silicon feature variety process schemes test important hypotheses reproduce them under more defined conditions. Different surface passivation based aluminium oxide layers combined with...
Gallium-doped silicon material has been rapidly gaining importance in the photovoltaic industry as a boron-oxygen defect-free with promising minority carrier lifetime.We investigate influence of different cell process flows [passivated emitter and rear tunneling-oxide-passivating contact, "hot oxidation" process] on bulk quality an industrial Ga-doped Cz-grown material, well its lightand elevated temperature induced degradation behavior under light at temperature.We measure generally high...
In this work, the established method of iron imaging is transferred from B‐doped silicon to Ga‐doped material. For purpose, pairing and splitting conditions are investigated a preparation procedure suggested that ensures sufficient fraction iron–gallium splitting, respectively. Furthermore defect parameters available in literature compared evaluated for suitable description injection dependent carrier lifetime measurements. A parameter set enables coherent adequate evaluation suggested....
Improving electrical and optical properties is important in manufacturing high-efficiency solar cells. Previous studies focused on individual gettering texturing methods to improve cell material quality reduce reflection loss, respectively. This study presents a novel method called saw damage with that effectively combines both for multicrystalline silicon (mc-Si) wafers manufactured using the diamond wire sawing (DWS) method. Although mc-Si not Si currently used photovoltaic products,...
In this work the existing SRH parametrizations for FeGa defect are re-evaluated by a deliberately iron contaminated sample set of varied doping densities. The evolution cross-over point is analyzed aim, due to its characteristic dependency on parameters metastable states. It can give insight into parameter, whilst being independent most factors usually limiting evaluations precision. proposed parameter adjustment provides an improved description measurement data compared literature parametrizations.