Publications de Christophe Ballif

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Reliable and esthetically pleasing lightweight photovoltaic modules for building integration are expected to grow interest in the consumer market, especially for retrofitting older buildings and storehouses that are not structurally designed to withstand a ...

The quest for increased performances in thin film silicon Micromorph tandem devices nowadays requires an increase of current density. This can be achieved with thin cells by combining both a robust cell design and efficient light management schemes. In this work we identify three key requirements for the transparent conductive oxide electrodes. Firstly, strong light scattering into large angles is needed on the entire useful wavelength range: a front electrode texture with large enough features is shown to

The integration of passivating contacts based on a highly doped polycrystalline silicon (poly-Si) layer on top of a thin silicon oxide (SiOx) layer has been identified as the next step to further increase the conversion efficiency of current mainstream cry ...

The front transparent conductive oxide layer is a source of significant optical and electrical losses in silicon heterojunction solar cells because of the trade-off between free-carrier absorption and sheet resistance. We demonstrate that hydrogen-doped in ...

Amorphous/crystalline silicon heterojunction (SHJ) solar cells technology is attracting tremendous attention in recent years due to its potential to achieve high power conversion efficiencies at low fabrication temperatures and using few process steps. How ...

The performances of thin film silicon solar cells are reported for the use of increasingly rough zinc-oxide (ZnO) front electrodes. Experimental results show that textured substrates favor increased light trapping but also the local creation of undesired current drains, degrading the electrical performance of the cells. While an appropriate plasma treatment of the ZnO surface and a high silicon material quality are required to decrease the density of such current drains, doped nano-crystalline silicon oxide

The primary performance limitation in inverted perovskite-based solar cells is the interface between the fullerene-based electron transport layers and the perovskite. Atomic layer deposited thin aluminum oxide (AlOX) interlayers that reduce nonradiative re ...

The fundamental sheet conductance of graphene can be directly related to the product of its absorption coefficient, thickness and refractive index. The same can be done for graphene's fundamental opacity if the so-called thin-film limit is considered. Here ...

A key step in industrialization of photovoltaics (PV) is the development of low-cost and large-area metallization processes to substitute the standard screen-printing process of silver paste. Thus Cu and Ni metallization processes enabled by laser patterni ...

This work reports the electrical characterization of ZnSnx Ge1 - xN2 (ZTGN) layers (10% < x < 90%) deposited on glass by combinatorial sputtering and further assesses the performance of silicon heterojunction (SHJ) solar cells featuring them as electron-se ...

Self-textured zinc oxide polycrystalline films prepared by metalorganic low-pressure chemical vapor deposition combine excellent transparency, conductivity and light-scattering ability when used as electrodes for high-efficiency thin-film silicon solar cel ...

We investigate light scattering interface textures for solar cells with the intention to obtain a more fundamental understanding of the absorption enhancement. Therefore, we study simplified structures with the periodic interface texture of sinusoidal and ...

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 ...

Conductive zinc oxide (ZnO) grown by low pressure chemical vapor deposition (LPCVD) technique possesses a rough surface that induces an efficient light scattering in thin film silicon (TF Si) solar cells, which makes this TCO an ideal candidate for contact ...

The increasing penetration of residential photovoltaics (PV) comes with numerous challenges for distribution system operators. Technical difficulties arise when an excess of PV energy is injected into the grid, causing voltage rise or overloading of the lines. Economic challenges appear because PV owners and consumers are not participating equally in the grid costs. Indeed, PV owners benefit by self-consuming their PV production and by gaining additional revenues when they sell their PV surplus to the grid.

This work investigates t the effectiveness of glass-glass solar PV module structures used in combination with a EVA as an encapsulant material. The use of EVA in glass-glass structures is in principle discouraged, as a bioproduct of its photo-degradation i ...

Hybrid vapor deposition is one of the most appealing processes for perovskite photovoltaics fabrication, thanks to its versatile nature. By using sequentially different vapor deposition processes tailored to the inorganic and organic perovskite precursors' ...

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 ...

Effect of grid feed-in curtailment of a PV system with heat or electricity storage (battery) is simulated as a function of system dimensioning with a focus on the induced PV power losses (due to this limit) and on cost balance. Heat storage is provided by a domestic hot water tank heated with heat pump or electrical water heating system. The case studied is based on a Swiss household with an annual electricity energy consumption of about 5000 kWh (without thermal loads). The effect of electricity generation

Full-area passivating contacts based on SiOx/poly-Si stacks are key for the new generation of industrial silicon solar cells substituting the passivated emitter and rear cell (PERC) technology. Demonstrating a potential efficiency increase of 1 to 2% compa ...

Christophe Ballif

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Novel Mechanically Robust and Environmentally Stable Light‐Weight Colored Photovoltaic Modules Based on Composite Polymer Backsheets

Optimization of ZnO Front Electrodes for High-Efficiency Micromorph Thin-Film Si Solar Cells

In Situ Reflectometry and Diffraction Investigation of the Multiscale Structure of p-Type Polysilicon Passivating Contacts for c-Si Solar Cells

Hydrogen-doped indium oxide/indium tin oxide bilayers for high-efficiency silicon heterojunction solar cells

Impact of the Oxygen Content on the Optoelectronic Properties of the Indium-Tin-Oxide Based Transparent Electrodes for Silicon Heterojunction Solar Cells

Low-conductivity doped layers for improved performance of thin film silicon solar cells on highly textured substrate

A Universal Perovskite/C60 Interface Modification via Atomic Layer Deposited Aluminum Oxide for Perovskite Solar Cells and Perovskite-Silicon Tandems

Effect of the thin-film limit on the measurable optical properties of graphene

Metallization of Si heterojunction solar cells by nanosecond laser ablation and Ni-Cu plating

Effects of Work Function and Electron Affinity on the Performance of Carrier-Selective Contacts in Silicon Solar Cells Using ZnSnx Ge-1 (-) N-x(2) as a Case Study

Tailoring the surface morphology of zinc oxide films for high-performance micromorph solar cells

Absorption Enhancement in Solar Cells With Periodic Interface Textures of Asymmetric Shape

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

Polycrystalline ZnO:B grown by LPCVD as TCO for thin film silicon solar cells

Impact of advanced electricity tariff structures on the optimal design, operation and profitability of a grid-connected PV system with energy storage

EVA for Glass/Glass Solar PV Modules: Effect of encasulant storage conditions and process parameters

Pizza Oven Processing of Organohalide Perovskites (POPOP): A Simple, Versatile and Efficient Vapor Deposition Method

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

Peak Shaving Capability of Household Grid-Connected PV-System with Local Storage: A Case Study

Development and characterization of N2O-plasma oxide layers for high-temperature p-type passivating contacts in silicon solar cells