Home

Person

Stefaan De Wolf

This person has left EPFL

About
Privacy
Disclaimer

Graph Chatbot

Related publications (78)

Page 3 of 4

High-efficiency crystalline silicon solar cells: status and perspectives

Stefaan De Wolf, Corsin Battaglia

With a global market share of about 90%, crystalline silicon is by far the most important photovoltaic technology today. This article reviews the dynamic field of crystalline silicon photovoltaics from a device-engineering perspective. First, it discusses ...

Royal Society of Chemistry2016

Efficient Monolithic Perovskite/Silicon Tandem Solar Cell with Cell Area >1 cm

Ching-Hsun Weng, Christophe Ballif, Stefaan De Wolf, Björn Niesen, Jérémie Werner, Arnaud Walter, Johannes Peter Seif, Luc Fesquet

Monolithic perovskite/crystalline silicon tandem solar cells hold great promise for further performance improvement of well-established silicon photovoltaics; however, monolithic tandem integration is challenging, evidenced by the modest performances and s ...

Amer Chemical Soc2016

Field-effect passivation on silicon nanowire solar cells (vol 8, pg 673, 2015)

Anna Fontcuberta i Morral, Stefaan De Wolf, Bénédicte Demaurex, Anna Dalmau Mallorquí

Surface recombination represents a handicap for high-efficiency solar cells. Surface recombination represents a handicap for high-efficiency solar cells. This is especially important for nanowire array solar cells, where the surface-to-volume ratio is grea ...

Tsinghua Univ Press2016

Field-effect passivation on silicon nanowire solar cells

Anna Fontcuberta i Morral, Stefaan De Wolf, Esther Alarcon Llado, Bénédicte Demaurex, Anna Dalmau Mallorquí

Surface recombination represents a handicap for high-efficiency solar cells. This is especially important for nanowire array solar cells, where the surface-to-volume ratio is greatly enhanced. Here, the effect of different passivation materials on the effe ...

Tsinghua Univ Press2015

Below the Urbach Edge: Solar Cell Loss Analysis Based on Full External Quantum Efficiency Spectra

Stefaan De Wolf, Jakub Holovsky, Xin Yu Chin

We suggest a new solar cell loss analysis using theexternal quantumefficiency (EQE) measured with sufficiently high sensitivity to alsoaccount for defects. Unlike common radiative-limit methods, wherethe impact of deep defects is ignored by exponential ext ...

AMER CHEMICAL SOC2023

Amorphous silicon enhanced metal-insulator-semiconductor contacts for silicon solar cells

Aïcha Hessler-Wyser, Stefaan De Wolf, Bénédicte Demaurex

Carrier recombination at the metal-semiconductor contacts has become a significant obstacle to the further advancement of high-efficiency diffused-junction silicon solar cells. This paper provides the proof-of-concept of a procedure to reduce contact recom ...

American Institute of Physics2014

Back-Contacted Silicon Heterojunction Solar Cells With Efficiency >21%

Christophe Ballif, Antoine Descoeudres, Stefaan De Wolf, Andrea Tomasi, Bertrand Yves Paul Paviet-Salomon, Jonas Geissbühler, Silvia Martin de Nicolas Agut

We report on the fabrication of back-contacted silicon heterojunction solar cells with conversion efficiencies above 21%. Our process technology relies solely on simple and size-scalable patterning methods, with no high-temperature steps. Using in situ sha ...

Ieee-Inst Electrical Electronics Engineers Inc2014

Profilometry of thin films on rough substrates by Raman spectroscopy

Christophe Ballif, Stefaan De Wolf, Matthieu Despeisse, Bertrand Yves Paul Paviet-Salomon, Jonas Geissbühler, Andrea Tomasi, Martin Ledinsky

Thin, light-absorbing films attenuate the Raman signal of underlying substrates. In this article, we exploit this phenomenon to develop a contactless thickness profiling method for thin films deposited on rough substrates. We demonstrate this technique by ...

Nature Research2016

22.5% efficient silicon heterojunction solar cell with molybdenum oxide hole collector

Christophe Ballif, Stefaan De Wolf, Aïcha Hessler-Wyser, Matthieu Despeisse, Björn Niesen, Sylvain Nicolay, Loris Barraud, Jérémie Werner, Andrea Tomasi

Substituting the doped amorphous silicon films at the front of silicon heterojunction solar cells with wide-bandgap transition metal oxides can mitigate parasitic light absorption losses. This was recently proven by replacing p-type amorphous silicon with ...

American Institute of Physics2015

Is light-induced degradation of a-Si:H/c-Si interfaces reversible?

Christophe Ballif, Stefaan De Wolf, El Mahdi El Mhamdi, Jakub Holovsky, Bénédicte Demaurex

Thin hydrogenated amorphous silicon (a-Si:H) films deposited on crystalline silicon (c-Si) surfaces are sensitive probes for the bulk electronic properties of a-Si:H. Here, we use such samples during repeated low-temperature annealing and visible-light soa ...

AIP American Institute of Physics2014

Silicon heterojunction solar cell with passivated hole selective MoOx contact

Christophe Ballif, Stefaan De Wolf, Corsin Battaglia

We explore substoichiometric molybdenum trioxide (MoOx, x < 3) as a dopant-free, hole-selective contact for silicon solar cells. Using an intrinsic hydrogenated amorphous silicon passivation layer between the oxide and the silicon absorber, we demonstrate ...

American Institute of Physics2014

Back-Contacted Silicon Heterojunction Solar Cells: Optical-Loss Analysis and Mitigation

Christophe Ballif, Stefaan De Wolf, Matthieu Despeisse, Sylvain Nicolay, Loris Barraud, Antoine Descoeudres, Bertrand Yves Paul Paviet-Salomon, Andrea Tomasi

We analyze the optical losses that occur in interdigitated back-contacted amorphous/crystalline silicon heterojunction solar cells. We show that in our devices, the main loss mechanisms are similar to those of two-side contacted heterojunction solar cells. ...

Ieee-Inst Electrical Electronics Engineers Inc2015

Environmental stability of high-mobility indium-oxide based transparent electrodes

Christophe Ballif, Stefaan De Wolf, Monica Morales Masis, Ali Dabirian

Large-scale deployment of a wide range of optoelectronic devices, including solar cells, critically depends on the long-term stability of their front electrodes. Here, we investigate the performance of Sn-doped In2O3 (ITO), H-doped In2O3 (IO:H), and Zn-dop ...

Amer Inst Physics2015

Organic-Inorganic Halide Perovskites: Perspectives for Silicon-Based Tandem Solar Cells

Christophe Ballif, Jun Ho Yum, Franz-Josef Haug, Stefaan De Wolf, Björn Niesen, Soo-Jin Moon, Jakub Holovsky, Martin Ledinsky

We investigate the efficiency potential of organic-inorganic halide perovskite/crystalline silicon tandem solar cells, a new class of photovoltaic devices targeting long-term cost reductions by ultrahigh conversion efficiencies. Methyl ammonium lead triiod ...

Ieee-Inst Electrical Electronics Engineers Inc2014

Low-temperature plasma-deposited silicon epitaxial films: Growth and properties

Christophe Ballif, Stefaan De Wolf, Duncan Thomas Lindsay Alexander, Quentin Thomas Jeangros, Johannes Peter Seif, Bénédicte Demaurex

Low-temperature (

American Institute of Physics2014

Scanning Laser-Beam-Induced Current Measurements of Lateral Transport Near-Junction Defects in Silicon Heterojunction Solar Cells

Christophe Ballif, Stefaan De Wolf, Antoine Descoeudres

We report the results of scanning laser-beam-induced current (LBIC) measurements on silicon heterojunction solar cells that indicate the length scale over which photogenerated carriers are sensitive to local defects at the amorphous silicon/crystalline sil ...

Ieee-Inst Electrical Electronics Engineers Inc2014

Transparent Electrodes for Efficient Optoelectronics

Christophe Ballif, Stefaan De Wolf, Monica Morales Masis

With the development of new generations of optoelectronic devices that combine high performance and novel functionalities (e.g., flexibility/bendability, adaptability, semi or full transparency), several classes of transparent electrodes have been develope ...

2017

Sputtered rear electrode with broadband transparency for perovskite solar cells

Christophe Ballif, Monica Morales Masis, Soo-Jin Moon, Sylvain Nicolay, Stefaan De Wolf, Philipp Friedrich Hermann Löper, Jérémie Werner, Björn Niesen, Guy Joseph Günter Dubuis, Arnaud Walter

Due to their high efficiencies combined with simple and cost-effective device fabrication, perovskite solar cells are promising candidates as top cells in tandem devices. For this application, the perovskite solar cell must be highly transparent at near-in ...

Elsevier2015

Organometallic Halide Perovskites: Sharp Optical Absorption Edge and Its Relation to Photovoltaic Performance

Christophe Ballif, Jun Ho Yum, Franz-Josef Haug, Stefaan De Wolf, Björn Niesen, Soo-Jin Moon, Jakub Holovsky, Martin Ledinsky

Solar cells based on organometallic halide perovskite absorber layers are emerging as a high-performance photovoltaic technology. Using highly sensitive photothermal deflection and photocurrent spectroscopy, we measure the absorption spectrum of CH3NH3PbI3 ...

Amer Chemical Soc2014

Kinetics of a-Si:H bulk defect and a-Si:H/c-Si interface-state reduction

Christophe Ballif, Stefaan De Wolf

Low-temperature annealing of hydrogenated amorphous silicon (a-Si:H) is investigated. An identical energy barrier is found for the reduction of deep defects in the bulk of a-Si:H films and at the interface such layers form with crystalline Si (c-Si) surfac ...

2012