Publications associées à Competition between excitons and exciplexes: Experiments on multilayered organic light emitting diodes

Shortwave Infrared-Sensitive, Narrowband Organic Upconversion Devices with a Gain

Sensing and imaging of light in the shortwave infrared (SWIR) range is increasingly used in various fields, including bio-imaging, remote sensing, and semiconductor process control. SWIR-sensitive organic photodetectors (OPDs) are promising because organic ...

EPFL2024

III-N blue-emitting epi-structures with high densities of dislocations: Fundamental mechanisms for efficiency improvement and applications

Pierre Christophe Lottigier

Since the dawn of humanity, human beings seeked to light their surroundings for their well-being, security and development. The efficiency of ancient lighting devices, e.g. oil lamps or candles, was in the order of 0.03-0.04% and jumped to 0.4-0.6% with th ...

EPFL2024

Study of growth-induced point defects and their impact on InGaN-based optoelectronic devices

Yao Chen

GaN exhibits a decomposition tendency for temperatures far below its melting point and common growth temperatures used in metal-organic vapour phase epitaxy (MOVPE).This characteristic is known to be a major obstacle for realising GaN bulk substrate. There ...

EPFL2024

Investigation of room-temperature single-photon emitters in GaN-based materials and GaN/AlN quantum dots

Johann Nicolaï Stachurski

Over the past decade, quantum photonics platforms aiming at harnessing the fundamental properties of single particles, such as quantum superposition and quantum entanglement, have flourished. In this context, single-photon emitters capable of operating at ...

EPFL2024

Structural divergence of molecular hole selective materials for viable p-i-n perovskite photovoltaics: a comprehensive review

Mohammad Khaja Nazeeruddin, Peng Gao, Paramaguru Ganesan

Perovskite solar cells (PSCs) have garnered significant attention within the photovoltaic research community due to their remarkable progress in just one decade. Among the device configurations, the p-i-n structured PSC offers several advantages, including ...

Royal Society of Chemistry2024

Investigating Non-equilibrium Physics in Wide Bandgap Semiconductors and Quantum Materials via Ultrafast Spectroscopy

Hui-Yuan Chen

This thesis uses femtosecond laser spectroscopy in studying strong correlation in condensed matters that are pertinent to future technology: a wide bandgap perovskite and a quantum material, with the employment of ultrafast time-resolved spectroscopy in th ...

EPFL2024

Enhancing Efficiency of Industrially-Compatible Monolithic Perovskite/Silicon Tandem Solar Cells with Dually-Mixed Self-Assembled Monolayers

Mohammad Khaja Nazeeruddin, Peng Gao, Ye Yang, Chaohui Li

The antisolvent-assisted spin-coating still lags behind the thermal evaporation method in fabricating perovskite films atop industrially textured silicon wafers in making monolithic perovskite/silicon solar cells (P/S-TSCs). The inhomogeneity of hole-selec ...

Wiley-V C H Verlag Gmbh2024

Towards Scalable Electronics: Synthetic 2D Materials for Large-Area 2D Circuit Integration

Zhenyu Wang

In the past decades, a significant increase of the transistor density on a chip has led to exponential growth in computational power driven by Moore's law. To overcome the bottleneck of traditional von-Neumann architecture in computational efficiency, effo ...

EPFL2024

Mott physics in the multiflavored age

Frédéric Mila

The multiflavor Mott insulators, whose local Hilbert space consists of multiple degrees of freedom, occur widely in both quantum materials and ultracold atom systems. This Comment recommends the review article by Chen and Wu that is, to the author's knowle ...

Nature Portfolio2024

MEMS-based Tunable Metasurface for Reflective Display Applications

Dorian Giraud Herle

In an era where portable electronic devices are indispensable for a wide range of activities, the need for displays that provide both long-lasting battery life and excellent visibility in different lighting conditions is increasingly important. Emissive di ...

EPFL2024

Persistent enhancement of exciton diffusivity in CsPbBr3 nanocrystal solids

Seryio Saris

In semiconductors, exciton or charge carrier diffusivity is typically described as an inherent material property. Here, we show that the transport of excitons among CsPbBr3 perovskite nanocrystals (NCs) depends markedly on how recently those NCs were occup ...

Amer Assoc Advancement Science2024

A comprehensive physical model for the sensitivity of silicon heterojunction photovoltaic modules to water ingress

Christophe Ballif, Alessandro Francesco Aldo Virtuani, Luca Gnocchi, Olatz Arriaga Arruti

Silicon heterojunction (SHJ)-solar modules-when encapsulated with ethylene vinyl acetate (EVA)-are known to be extremely sensitive to water ingress. The reason for this is, however, not clear. Here, we explain the root causes of this degradation mechanism ...

Cell Press2024

Computational Studies on the Stability of Organic-Inorganic Hybrid Halide Lead Perovskites

Mathias Dankl

Perovskite-based solar cells are currently the most rapidly advancing photovoltaic technology but concerns about their long-term stability are still impeding full-scale commercialization. This thesis provides computational insights into some of the stabili ...

EPFL2024

Durable Perovskite Solar Cells with 24.5% Average Efficiency: The Role of Rigid Conjugated Core in Molecular Semiconductors

Michael Graetzel, Shaik Mohammed Zakeeruddin, Peng Wang, Felix Thomas Eickemeyer, Ming Ren

Efficient and robust n-i-p perovskite solar cells necessitate superior organic hole-transport materials with both mechanical and electronic prowess. Deciphering the structure-property relationship of these materials is crucial for practical perovskite sola ...

Wiley-V C H Verlag Gmbh2024

Dataset to accompany publication "Best practices in measuring absorption at the macro- and microscale"

Giulia Tagliabue, Fateme Kiani Shahvandi, Jiaming Ma, Alan Richard Bowman

This dataset accompanies the publication "Best practices in measuring absorption at the macro- and microscale" published in APL Photonics. The data can be used to reproduce original plots in figures 1-4 in the main text and all original plots in the suppor ...

Zenodo2024

Assessing the Charge Carrier Dynamics at Hybrid Interfaces of Organic Photoanodes for Solar Fuels

Kevin Sivula, Yongpeng Liu, Han-Hee Cho, Alexander Wieczorek

Organic semiconductors (OSCs) have emerged as promising active layers for photoanodes to drive photoelectrochemical (PEC) oxidation reactions. Interfacing an OSC with an inorganic electron transport layer (ETL) is key to enabling both high performance and ...

Amer Chemical Soc2024

Photo-doping of spiro-OMeTAD for highly stable and efficient perovskite solar cells

Michael Graetzel, Jacques-Edouard Moser, Etienne Christophe Socie, Aaron Tomas Terpstra, George Cameron Fish, Kai Zhu

A widely used component of high-efficiency perovskite solar cells (PSCs) is the molecular hole-transport material (HTM) spiro-OMeTAD. This organic solid needs to be p-doped to acquire sufficient hole conductivity. However, the conventional doping method us ...

2024

Identification and Mitigation of Degradation Mechanisms Induced by Heat and Light in NiOx-based Perovskite Solar Cells

Marion Solange Madeleine Dussouillez

Perovskite solar cells (PSCs) offer an attractive solution to increase the efficiency of PV panels via perovskite/silicon tandems thanks to their potential cost-effectiveness and high efficiency. In inverted PSC architecture (p-i-n), commonly used hole con ...

EPFL2024

Ultra-high quantum coherent and scalable superconducting circuit optomechanics, from topological lattices to quantum storage

Amir Youssefi

Mechanical oscillators can exhibit modes with ultra-low energy dissipation and compact form factors due to the slow velocity of acoustic waves, and are already used in applications ranging from timing to wireless filters. Over the past decade, novel ways i ...

EPFL2024

Alleviating nanostructural phase impurities enhances the optoelectronic properties, device performance and stability of cesium-formamidinium metal-halide perovskites

Christophe Ballif, Aïcha Hessler-Wyser, Quentin Thomas Jeangros, Beat Ruhstaller, Mostafa Rabie Shlaly Bahr Othman, Daniel Anthony Jacobs, Christian Michael Wolff, Anaël Morgane Jaffrès, Austin George Kuba

The technique of alloying FA+ with Cs+ is often used to promote structural stabilization of the desirable alpha-FAPbI3 phase in halide perovskite devices. However, the precise mechanisms by which these alloying approaches improve the optoelectronic quality ...

Royal Soc Chemistry2024