Publications by Christophe Ballif

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The necessity to reduce carbon emissions has pushed European institutions to foster the adoption - for new buildings - of Nearly Zero Energy Buildings, which need to minimize energy consumption with energy generated on site. This opens up an enormous potential for the integration of renewable energy sources in the built environment. However, a massive introduction of PV into buildings should be accompanied by an increased sensitivity in terms of the aesthetic appeal of the modules. Inks masking the metallic

The TISO-10-kW solar plant, connected to the grid in 1982, is the oldest installation of this kind in Europe. Its history is well documented, and the full set of modules has been tested indoors at regular intervals over the years. After 35 years of operati ...

In this work, we analyze the effect of rough ZnO front electrodes developed in-house favoring high current versus "smoother" substrates favoring good Voc and FF on the properties of microcrystalline silicon (μc-Si:H) cells. Complete μc-Si:H p-i-n solar cells with intrinsic layer thicknesses varying from 1 to 6μm were deposited using very high frequency plasma-enhanced chemical vapor deposition. The better scattering capabilities of rough substrates induce a significantly higher cell current in comparison to

A systematic comparison of front- and rear-emitter silicon heterojunction solar cells produced on nand p-type wafers was performed, in order to investigate their potential and limitations for high efficiencies. Cells on p-type wafers suffer from reduced minority carrier lifetime in the low-carrier-injection range, mainly due to the asymmetry in interface defect capture cross sections. This leads to slightly lower fill factors than for n-type cells. However, these losses can be minimized by using high-qualit

Silicon heterojunction solar cells are crystalline silicon-based devices in which thin amorphous silicon layers deposited on the wafer surfaces serve as passivated, carrier-selective contacts. The success of this technology is attributable to the ability o ...

In Thin Film Silicon (TF-Si) solar cells light harvesting schemes must guarantee an efficient light trapping in the thin absorber layers without decreasing the silicon layers quality and consecutively the p-i-n diodes electrical performance. TF-Si solar ce ...

Profound changes driven by decarbonization, decentralization, and digitalization are disrupting the energy industry, bringing new challenges to its key stakeholders. In the attempt to address the climate change issue, increasing penetration of renewables a ...

We present a p-type passivating rear contact that complies with integration into standard solar cell manufacturing with phosphorus-diffused front side. Our contact structure consists of a thin SiOx tunneling layer grown by wet chemistry and a stack of laye ...

Electrical losses in silicon heterojunction (SHJ) solar cells are difficult to identify and to control as multiple material layers and several entangled physical phenomena are involved. In this context, this contribution aims to accurately investigate and ...

Tandem solar cells are a key technology for exceeding the theoretical efficiency limit of single-junction cells. One of the most promising combinations is the silicon-perovskite tandem cells, considering their potential for high efficiency, fabrication on ...

Passivating contacts are key enablers for high efficiency c-Si solar cells. Here, we present our latest advancement in terms of implementation and understanding in fired passivating contacts (FPC) used as rear p + passivating contact in p-type solar cells. ...

In the present work, we apply a 2D self consistent model of SiH4/H2 discharges in order to investigate the transition from microcrystalline to amorphous silicon growth. The model is used to examine the relative importance of ions and atomic hydrogen in the ...

We introduce passivating hetero-interfaces in single-junction microcrystalline silicon (mc-Si:H) solar cells. We investigate the effect of different i–n layer stacks in thin mc-Si:H devices, in which recombination is significant at the interfaces as well as in the bulk material. By applying amorphous silicon passivating layers at the mc-Si:H i–n interface, we show a device with a high open-circuit voltage (Voc) of 608 mV, for a standard Raman crystalline fraction of the i-layer (>50%). This Voc is the highe

Thin films with tunable porosity are of high interest in applications such as gas sensing and antireflective coatings. We report a facile and scalable method to fabricate ZnO electrodes with tuneable porosity. By adjusting the substrate temperature and rat ...

With the photovoltaics (PV) market reaching the terawatt scale, assessing the performance of PV systems accurately has become essential. Traditional approaches to fault detection and diagnosis (FDD) and performance loss rate (PLR) evaluation often operate ...

This paper investigates the potential of storing photovoltaic (PV) electricity in electric vehicle (EV) batteries and reinjecting the stored electricity into the grid (V2G) during high electricity demand periods. We developed a geographical methodology to quantify the mobility and EV charging needs across Europe. Scenarios of charging behaviour are then used to distribute the charging needs among locations corresponding to residential areas, workplaces, or points of interest (e.g., shops, restaurants, etc.)

We investigate bulk and interface recombination in crystalline silicon with p-type fired passivating contacts. These consist of a chemical oxide and an in-situ doped layer of SiCx with low carbon content. Following a rapid thermal annealing to activate the ...

Unveiling the correlation between elemental composition, Fermi-level splitting, and charge collection in perovskite solar cells (PSCs) when exposed to different environments is crucial to understanding the origin of defects. This will enable defect enginee ...

The properties and high-efficiency potential of frontand rear-emitter silicon heterojunction solar cells on n- and p-type wafers were experimentally investigated. In the low-carrierinjection range, cells on p-type wafers suffer from reduced minority carrier lifetime, mainly due to the asymmetry in interface defect capture cross sections. This leads to slightly lower fill factors than for n-type cells. By using high-quality passivation layers, however, these losses can be minimized. High open-circuit voltage

Two fundamental requirements of transparent conductive oxides are high conductivity and low optical absorptance, properties strongly dependent on the free-carrier concentration of the film. The free carrier concentration is usually-tuned by the addition of ...

Christophe Ballif

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Stability of inks used for masking metallic interconnects in BIPV modules

35 years of photovoltaics: Analysis of the TISO-10-kW solar plant, lessons learnt in safety and performance-Part 1

Substrate dependent stability and interplay between optical and electrical properties in μc-Si:H single junction solar cells

Silicon heterojunction solar cells on n- and p-type wafers with efficiencies above 20%

Amorphous Silicon/Crystalline Silicon Heterojunction Solar Cells

Light Harvesting Schemes for High Efficiency Thin Film Silicon Solar Cells

A Blockchain-Supported Framework for Charging Management of Electric Vehicles

A Mixed-Phase SiOx Hole Selective Junction Compatible With High Temperatures Used in Industrial Solar Cell Manufacturing

Bottom-Up and Top-Down Approaches for Identifying and Mitigating Electrical Losses in Silicon Heterojunction Solar Cells

Passivating contact-based tunnel junction Si solar cells using machine learning for tandem cell applications

Implementation and understanding of p plus fired rear hole selective tunnel oxide passivating contacts enabling > 22% conversion efficiency in p-type c-Si solar cells

Plasma Modelling and Diagnostics for the Prediction of Structural Changes in Silicon Thin Film Deposition Plasma Modelling and Diagnostics for the Prediction of Structural Changes in Silicon Thin Film Deposition

Microcrystalline silicon solar cells with passivated interfaces for high open-circuit voltage

Tuning the porosity of zinc oxide electrodes: from dense to nanopillar films

Detect, Decouple, Optimise: Insights into Solar Photovoltaics Faults and Performance Trends

Potential for EV Charging From PV: A Geographic Assessment

Impact of rapid thermal processing on bulk and surface recombination mechanisms in FZ silicon with fired passivating contacts

Charge Collection in Hybrid Perovskite Solar Cells: Relation to the Nanoscale Elemental Distribution

>21% Efficient Silicon Heterojunction Solar Cells on n- and p-Type Wafers Compared

Direct Imaging of Dopant Distribution in Polycrystalline ZnO Films