A5003924249- Perovskite Materials and Applications
- Thin-Film Transistor Technologies
- Silicon and Solar Cell Technologies
- Chalcogenide Semiconductor Thin Films
- Quantum Dots Synthesis And Properties
- Conducting polymers and applications
- Semiconductor materials and interfaces
- Advancements in Solid Oxide Fuel Cells
- Organic Electronics and Photovoltaics
- ZnO doping and properties
- Silicon Nanostructures and Photoluminescence
- Electronic and Structural Properties of Oxides
- Electrocatalysts for Energy Conversion
- Integrated Circuits and Semiconductor Failure Analysis
- Ion-surface interactions and analysis
- Solid-state spectroscopy and crystallography
- Electron and X-Ray Spectroscopy Techniques
- Nanowire Synthesis and Applications
- solar cell performance optimization
- Gas Sensing Nanomaterials and Sensors
- Transition Metal Oxide Nanomaterials
- Advanced Materials Characterization Techniques
- Advanced battery technologies research
- Organic Light-Emitting Diodes Research
- Semiconductor materials and devices
Swiss Center for Electronics and Microtechnology (Switzerland)
2022-2025
École Polytechnique Fédérale de Lausanne
2015-2024
University of Neuchâtel
2021
Thinfilm (Sweden)
2016-2019
University of Basel
2016-2018
Silicon solar cells are approaching their theoretical efficiency limit of 29%. This limitation can be exceeded with advanced device architectures, where two or more stacked to improve the harvesting energy. In this work, we devise a tandem perovskite layer conformally coated on silicon bottom cell featuring micrometric pyramids—the industry standard—to its photocurrent. Using an additive in processing sequence, regulate crystallization process and alleviate recombination losses occurring at...
Abstract Perovskite/silicon tandem solar cells are increasingly recognized as promising candidates for next‐generation photovoltaics with performance beyond the single‐junction limit at potentially low production costs. Current designs monolithic tandems rely on transparent conductive oxides an intermediate recombination layer, which lead to optical losses and reduced shunt resistance. An improved junction based nanocrystalline silicon layers mitigate these is demonstrated. When employed in...
We reveal an iodine vapor-induced degradation mechanism in formamidinium–lead-iodide-based perovskite solar cells stressed under combined heat and light illumination.
A monolithic two-terminal perovskite/silicon tandem solar cell based on an industrial, high-temperature tolerant p-type crystalline silicon bottom with a steady-state power conversion efficiency of 25.1% is demonstrated.
Abstract The presence of mobile ions in metal halide perovskites has been shown to adversely affect the intrinsic stability perovskite solar cells (PSCs). However, actual contribution total degradation loss compared with other factors such as trap-assisted recombination remains poorly understood. Here we reveal that ion-induced internal field screening is dominant factor PSCs under operational conditions. increased leads a decrease steady-state efficiency, often owing large reduction current...
While perovskite-based photovoltaics is progressing toward commercialization, it remains an open question which fabrication technology – solution-based, vapor-based, or combinations will pave the way to faster economic breakthrough.
Perovskite-silicon (Si) tandem solar cells are the most prominent contenders to succeed single-junction Si that dominate market today. Yet, justify added cost of inserting a perovskite cell on top Si, these devices should first exhibit sufficiently high power conversion efficiencies (PCEs). Here, we present two key developments with synergetic effect boost PCEs our front-side flat wafers—the use 2,3,4,5,6-pentafluorobenzylphosphonic acid (pFBPA) in precursor ink suppresses recombination near...
Abstract The primary performance limitation in inverted perovskite‐based solar cells is the interface between fullerene‐based electron transport layers and perovskite. Atomic layer deposited thin aluminum oxide (AlO X ) interlayers that reduce nonradiative recombination at perovskite/C 60 are developed, resulting >60 millivolts improvement open‐circuit voltage 1% absolute power conversion efficiency. Surface‐sensitive characterizations indicate presence of a thin, conformally AlO x layer,...
Low‐resistance contact to lightly doped n‐type crystalline silicon (c‐Si) has long been recognized as technologically challenging due the pervasive Fermi‐level pinning effect. This hindered development of certain devices such c‐Si solar cells made with partial rear contacts (PRC) directly lowly wafer. Here, a simple and robust process is demonstrated for achieving mΩ cm 2 scale resistivities on via lithium fluoride/aluminum contact. The realization this low‐resistance enables fabrication...
Changes in the nanostructure of methylammonium lead iodide (MAPbI3) perovskite solar cells are assessed as a function current–voltage stimulus by biasing thin samples situ transmission electron microscope. Various degradation pathways identified both and ex situ, predominantly at positively biased MAPbI3 interface. Iodide migrates into charge transport layer also volatilizes along with organic species, which triggers nucleation PbI2 nanoparticles voids hence decreases cell performance.
Recent advances in the efficiency of crystalline silicon (c‐Si) solar cells have come through implementation passivated contacts that simultaneously reduce recombination and resistive losses within contact structure. In this contribution, low resistivity are demonstrated based on reduced titania (TiO x ) contacted with work function metal, calcium (Ca). By using Ca as overlying metal structure we able to achieve a reduction TiO up two orders magnitude compared previously reported data Al/TiO...
Interfacial engineering of the meso-TiO2 surface through a modified sequential deposition procedure involving novel PbI2–HMPA complex pretreatment is conducted as reproducible method for preparing MAPbI3 based perovskite solar cells providing highest efficiencies yet reported with polymer HTM layer. Grazing-incidence X-ray diffraction depth profiling confirms formation film PbI2-rich region close to electron transport layer (ETL) due strong interaction HMPA PbI2, which successfully retarded...
Cesium–formamidinium-based mixed-halide perovskite materials with optical band gaps ranging from 1.5 to 1.8 eV are investigated by variable-angle spectroscopic ellipsometry. The determined complex refractive indices shown depend on the fabrication procedure and environmental conditions during processing. This data is complemented additional structural characterization, as well demonstration of efficient solar cells. Finally, used in simulations provide guidelines for optimization...
The mechanisms controlling the degradation of p–i–n perovskite solar cells in reverse bias are identified using various optoelectronic and microstructural characterization techniques.
High efficiency triple-junction solar cells are currently made of III–V semiconductors using expensive deposition methods. Perovskite/perovskite/silicon monolithic could be a lower-cost alternative as no epitaxial growth is required. We demonstrate here that such devices can realized textured crystalline silicon bottom for optimal light management. By changing the perovskite absorbers composition and recombination junctions to make them compatible with subsequent fabrication steps,...
Copper electroplating is investigated and compared with common silver printing techniques for the front metallization of silicon heterojunction solar cells. We achieve smaller feature sizes by electroplating, significantly reducing optical shadowing losses improving cell efficiency 0.4% absolute. A detailed investigation series resistance contributions reveals that, at maximum power point, a significant part lateral charge-carrier transport occurs inside crystalline bulk, rather than...
Flexible large‐area organic light‐emitting diodes (OLEDs) require highly conductive and transparent anodes for efficient uniform light emission. Tin‐doped indium oxide (ITO) is the standard anode in industry. However, due to scarcity of indium, alternative that eliminate its use are desired. Here an indium‐free developed by a combinatorial study zinc (ZnO) tin (SnO 2 ), both composed earth‐abundant elements. The optimized Zn–Sn–O (ZTO) films have electron mobilities up 21 cm V −1 s ,...