Concept

Quasi Fermi level

Publications associées (14)

Correlating chemical and electronic states from quantitative photoemission electron microscopy of transition-metal dichalcogenide heterostructures

Andras Kis, Dumitru Dumcenco, Olivier Renault, Dmitrii Unuchek, Hokwon Kim, Nicolas Chevalier

Vertical heterostructures of MoS2 and WSe2 layers are studied by spectroscopic photoemission electron microscopy as an effective technique for correlating chemical and electronic states at the micrometer scale. Element-specific, surface-sensitive images re ...

2021

Band-bending induced passivation: high performance and stable perovskite solar cells using a perhydropoly(silazane) precursor

Mohammad Khaja Nazeeruddin, Yi Zhang, Mounir Driss Mensi, Hiroyuki Kanda, Sanghyun Paek, Giulia Grancini, Yonghui Lee, Kyung Taek Cho, Cristina Roldán Carmona, Aron Joel Huckaba, Valentin Ianis Emmanuel Queloz, Mo Li, Nadja Isabelle Desiree Klipfel

Surface passivation of the perovskite photo absorber is a key factor to improve the photovoltaic performance. So far robust passivation strategies have not yet been revealed. Here, we demonstrate a successful passivation strategy which controls the Fermi-l ...

2020

A Self-Assembled Organic/Metal Junction for Water Photo-Oxidation

Hubert Girault, Natalia Gasilova, Astrid Johana Olaya Avendano, Victor Costa Bassetto, Jonnathan Cesar Hidalgo Acosta, Julieta Soledad Riva, Terumasa Omatsu

We report the in situ self-assembly of TTF, TTF•+, and BF4 − or PF6 − into p-type semiconductors on the surface of Pt microparticles dispersed in water/acetonitrile mixtures. The visible light photoactivation of these selfassemblies leads to water oxidatio ...

2019

Passivation, conductivity, and selectivity in solar cell contacts: Concepts and simulations based on a unified partial-resistances framework

Mathieu Gérard Boccard

Passivation, conductivity, and selectivity are often acknowledged as the three requirements for optimal contacts to photovoltaic solar cells. Although there are generally accepted definitions and metrics for passivation and conductivity, a common understan ...

2019

Self-compensation due to point defects in Mg-doped GaN

Alfredo Pasquarello, Giacomo Francesco Leonardo Miceli

Using hybrid density functional theory, we address point defects susceptible to cause charge compensation upon Mg doping of GaN. We determine the free energy of formation of the nitrogen vacancy and of several Mg-related defects. The entropic contribution ...

Amer Physical Soc2016

Mixed interlayers at the interface between PEDOT:PSS and conjugated polymers provide charge transport control

Wolfgang Richard Tress, Jun Li, Mina Jung

Poly(3,4-ethylenedioxythiophene)-poly(styrenesulphonate) (PEDOT:PSS) is the most used organic hole injecting or hole transporting material. The hole carrying matrix PEDOT is highly doped by the acidic dopant PSS. When coated onto a substrate, PEDOT: PSS ma ...

Royal Society of Chemistry2015

Light-induced Voc increase and decrease in high-efficiency amorphous silicon solar cells

Christophe Ballif, Franz-Josef Haug, Jan-Willem Alexander Schüttauf, Matthieu Despeisse, Michael Elias Stückelberger, Yannick Samuel Riesen

High-efficiency amorphous silicon (a-Si:H) solar cells were deposited with different thicknesses of the p-type amorphous silicon carbide layer on substrates of varying roughness. We observed a light-induced open-circuit voltage (Voc) increase upon light so ...

American Institute of Physics2014

Dynamics of photogenerated holes in surface modified alpha-Fe2O3 photoanodes for solar water splitting

Michael Graetzel, Kevin Sivula, Takashi Hisatomi

This paper addresses the origin of the decrease in the external electrical bias required for water photoelectrolysis with hematite photoanodes, observed following surface treatments of such electrodes. We consider two alternative surface modifications: a c ...

National Academy of Sciences2012

On the Morphology and Interfaces of Nanostructured Hematite Photoanodes for Solar-Driven Water Splitting

Florian Le Formal

A sustainable route to store the energy provided by the Sun, is to directly convert sunlight into molecular hydrogen using a semiconductor performing water photolysis. Hematite (α-Fe2O3) is promising for this application due to its ample abundance, chemica ...

EPFL2011

Formation of substoichiometric GeOx at the Ge-HfO2 interface

Alfredo Pasquarello, Peter Broqvist, Jan Felix Binder

The stability of oxygen vacancies across the Ge-HfO2 interface is studied through semilocal and hybrid density-functional calculations. On the semiconductor side, the formation energies are obtained for substoichiometric GeOx of varying x through the use o ...

American Institute of Physics2010

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