Publications associées à Ultrafast carrier dynamics and insights in defect mechanism of p-type colloidal ZnO QDs

Tailoring p-Type Behavior in ZnO Quantum Dots through Enhanced Sol–Gel Synthesis: Mechanistic Insights into Zinc Vacancies

Jacques-Edouard Moser, Andrea Cannizzo, Etienne Christophe Socie, Camila Bacellar Cases Da Silveira, Victoria Kabanova

The synthesis and control of properties of p-type ZnO is crucial for a variety of optoelectronic and spintronic applications; however, it remains challenging due to the control of intrinsic midgap (defect) states. In this study, we demonstrate a synthetic ...

2024

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

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

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

Exciton migration in two-dimensional materials

Excitons play an essential role in the optical response of two-dimensional materials. These are bound states showing up in the band gaps of many-body systems and are conceived as quasiparticles formed by an electron and a hole. By performing real-time simu ...

Nature Portfolio2024

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

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

Elimination of buried interfacial voids for efficient perovskite solar cells

Bo Chen, Bin Ding, Yan Liu, Xianfu Zhang

Establishing optimal interfacial contact is crucial for enhancing the efficiency of perovskite solar cells (PSCs). However, formation of voids at buried interface of perovskite films often hinders this critical objective. Our investigation reveals that the ...

Elsevier2024

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

Investigating the Effect of Crystal Morphology on Optoelectronic Properties of Zinc Phosphide Thin Films via Optical-pump Terahertz Probe Spectroscopy

Elias Zsolt Stutz, Jean-Baptiste Leran, Léa Buswell, Mahdi Zamani, Simon Robert Escobar Steinvall, Rajrupa Paul, Mirjana Dimitrievska

Zinc phosphide ( Zn3P2) is a promising earth-abundant material for solar cell applications but calls for the further understanding of its optoelectronic properties. In this work, we perform contact-free and noninvasive optical-pump terahertz probe (OPTP) s ...

IEEE2023

Zn3P2 as an earth-abundant photovoltaic material: from growth to device

Rajrupa Paul

The development of cost-effective and earth-abundant semiconducting materials is imperative for the sustainable deployment of photovoltaic technology. Zinc phosphide (Zn3P2) is a promising candidate for terawatt-scale electricity generation. It has a near- ...

EPFL2023

Silica aerogel as rear reflector in silicon heterojunction solar cells for improved infrared response

Deniz Türkay

Silicon (Si), with its indirect bandgap, is a non-ideal absorber. Thus, various strategies to boost silicon solar cells' efficiency, including advanced texturing, multilayer anti-reflecting coating, and rear reflectors are utilized. Dielectrics, deposited ...

ELSEVIER2023

Interface connection of functionalized carbon nanotubes for efficient and stable perovskite solar cells

Mohammad Khaja Nazeeruddin, Ruiyuan Hu, Jianxing Xia

The ionic defects of hetero-junction interfaces always attract and trap carriers via surface electrostatic forces, which are crucial for the efficiency and intrinsic stability of perovskite solar cells (PSCs). Herein, functionalized carbon nanotubes (CNTs) ...

Royal Society of Chemistry2023

Investigation and Mitigation of Moisture- and Potential-Induced Degradation Mechanisms of Silicon Heterojunction Solar Cells and Modules

Olatz Arriaga Arruti

Photovoltaic (PV) technology is one of the most promising renewable energy sources. The PV market is dominated by crystalline silicon (c-Si) based technologies, thus ensuring their long-term performance is of paramount importance for manufacturers, investo ...

EPFL2023

Indoor Self-Powered Perovskite Optoelectronics with Ultraflexible Monochromatic Light Source

Felix Thomas Eickemeyer, Tommaso Marcato, Hiroaki Jinno, Lukas Pfeifer

Self-powered skin optoelectronics fabricated on ultrathin polymer films is emerging as one of the most promising components for the next-generation Internet of Things (IoT) technology. However, a longstanding challenge is the device underperformance owing ...

Wiley-V C H Verlag Gmbh2023

Photoelectrochemical Cell Engineering for Solar Energy Conversion

Dan Zhang

Solar energy is the most abundant energy source, harnessing solar energy holds the solution to the challenge of increasing global energy demand and reducing our dependence on fossil fuels. Photovoltaics which directly convert solar energy into electricity ...

EPFL2023

Charge Extraction and Recombination Dynamics of CdSe/CdTe Solar Cells Studied with Transient Photovoltage/Photocurrent Techniques

Mohammad Khaja Nazeeruddin, Iwan Zimmermann, Lei Chen

Significant advancements have been made in the development of high-performance cadmium telluride (CdTe)-based thin film solar cells. However, studies examining the transient excited-state charge dynamics, which determine the final steady-state device perfo ...

IEEE2023

Potential-induced degradation in bifacial silicon heterojunction solar modules: Insights and mitigation strategies

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

Potential-induced degradation (PID) may be a serious concern in photovoltaic (PV) modules and plants, particularly when approaching high system voltages (1500+ V). Here, we investigate PID occurring in bifacial rear-emitter silicon heterojunction (SHJ) sol ...

Wiley2023

Chemical Trend of Nonradiative Recombination in Cu(In,Ga)Se2 Alloys

Stefano Falletta

Nonradiative recombination in Cu(In,Ga)Se2 (CIGS) solar cells has long been attributed to the antisite defects MCu (M = In, Ga), but the underlying mechanism is still elusive. Using rigorous first-principles calculations, we demonstrate that the antisites ...

American Physical Society (APS)2023

III-V Nitride Semiconductors Deposited At Low Temperature For Photovoltaic Applications

Jonathan Emanuel Thomet

This thesis reports on the study and use of low temperature processes for the deposition of indium gallium nitride (InGaN) thin films in order to alleviate some of the present drawbacks of its monolitic deposition on silicon for photovoltaic applications. ...

EPFL2023