Publications de Klaus Leifer | EPFL Graph Search

Mechanistic Insights into the Role of the Bis(trifluoromethanesulfonyl) imide Ion in Coevaporated p-i-n Perovskite Solar Cells

Klaus Leifer, Keith Gregory Brooks, Mohammad Khaja Nazeeruddin, Mounir Driss Mensi, Paul Joseph Dyson, Cristina Roldán Carmona, Hiroyuki Kanda, Cansu Igci, Nadja Isabelle Desiree Klipfel, Albertus Adrian Sutanto, Maria Cristina Momblona Rincón

Hybrid lead halide perovskites have reached comparable efficiencies to state-of-the-art silicon solar cell technologies. However, a remaining key challenge toward commercialization is the resolution of the perovskite device instability. In this work, we id ...

2021

Coronene Fusion by Heat Treatment: Road to Nanographenes

Klaus Leifer, Yury Tsybin

The reactions of coronene dehydrogenation and fusion upon heat treatment in the temperature range of 500-700 degrees C were studied using XRD, TEM, Raman, IR, and NEXAFS spectroscopy. The formation of a coronene dimer (dicoronylene) was observed at tempera ...

American Chemical Society2011

Decomposition, diffusion, and growth rate anisotropies in self-limited profiles during metalorganic vapor-phase epitaxy of seeded nanostructures

Klaus Leifer, Elyahou Kapon, Alok Rudra

We present a model for the interplay between the fundamental phenomena responsible for the formation of nanostructures by metalorganic vapor phase epitaxy on patterned (001)/(111)B GaAs substrates. Experiments have demonstrated that V-groove quantum wires ...

2011

Mechanisms of Quantum Dot Energy Engineering by Metalorganic Vapor Phase Epitaxy on Patterned Nonplanar Substrates

Klaus Leifer, Benjamin Dwir, Elyahou Kapon, Paolo De Los Rios, Qing Zhu

A novel technique for tuning the strength of quantum confinement in site-controlled semiconductor quantum dots (QDs) is introduced and investigated theoretically and experimentally. The method makes use of controlled local growth rates during metalorganic ...

American Chemical Society2007

Strongly reduced exciton transfer between quantum wires

Klaus Leifer, Elyahou Kapon, Alok Rudra

AIP American Institute of Physics2007

Narrow (~4meV) inhomogeneous broadening and its correlation with confinement potential of pyramidal quantum dot arrays

Klaus Leifer, Benjamin Dwir, Elyahou Kapon

AIP American Institute of Physics2007

Influence of long-range substrate roughness in V-groove quantum wire structures

Klaus Leifer, Elyahou Kapon, Alok Rudra, Hakon Reichardt

2006

Polarization-Resolved Optical Absorption in Single V-groove Quantum Wires

Klaus Leifer, Marc-André Dupertuis, Elyahou Kapon, Alok Rudra, Susanna Palmgren

AIP American Institute of Physics2006

Alloy Segregation, Quantum Confinement and Carrier Capture in Self-Ordered Pyramidal Quantum Wires

Klaus Leifer, Marc-André Dupertuis, Elyahou Kapon, Sascha Dalessi, Qing Zhu

2006

Patterning of Confined-State Energies in Site-Controlled Semiconductor Quantum Dots

Klaus Leifer, Benjamin Dwir, Elyahou Kapon

AIP American Institute of Physics2005

Enhancement of the binding energy of charged excitons in disordered quantum wires

Klaus Leifer, Marc-André Dupertuis, Benjamin Dwir, Elyahou Kapon, Daniel Oberli, Nicolas Moret

Negatively and positively charged excitons are identified in the spatially resolved photoluminescence spectra of quantum wires. We demonstrate that charged excitons are weakly localized in disordered quantum wires. As a consequence, the enhancement of the ...

2005