Publications by Christophe Ballif

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Thin Film on ASIC (TFA) technology combines advantages of two commonly used pixel imaging detectors, namely, Monolithic Active Pixels (MAPs) and Hybrid Pixel detectors. Thanks to direct deposition of a hydrogenated amorphous silicon (a- Si:H) sensor lm on ...

The deposition of a stack of amorphous (a-Si:H) and microcrystalline (µc- Si:H) tandem thin film silicon solar cells (micromorph) requires at least twice the time used for a single junction a-Si:H cell. However, micromorph devices have a higher potential e ...

The effect of substrate morphology on the growth and electrical properties of single-junction microcrystalline silicon cells is investigated. A large variety of V-shaped and U-shaped substrates are characterized by scanning electron microscopy (SEM) and th ...

Microcrystalline silicon is a composite material embedding silicon nanocrystals in an amorphous matrix [1]. It has attracted much research efforts in the photovoltaic domain [2], because of its potential for integration in a tandem cell concept as bottom c ...

We demonstrate high-efficiency perovskite–silicon tandem solar cells using double-sided tunnel oxide passivated contacts (TOPCon2) bottom cells, achieving 30.2% efficiency on both-sides flat and 31.3% on front-textured devices. The former is enabled by high passivation quality on flat surfaces and the latter by enhanced optical performance. These results highlight that TOPCon2 is a promising platform for scalable tandem integration beyond silicon heterojunction-based bottom cells.

There is general agreement that the future production of electric energy has to be renewable and sustainable in the long term. Photovoltaic (PV) is booming with more than 7GW produced in 2008 and will therefore play an important role in the future electric ...

We present a laser scribing system for mid-size photovoltaic modules (up to 410 × 520 mm2) implementing a movable diode-pumped solid state laser. In this configuration, the heavy large-area photovoltaic module does not need to be displaced, allowing for fa ...

Photovoltaic (PV) module efficiency and reliability are two factors that have an important impact on the final cost of the PV electricity production. It is widely accepted that a good adhesion between the encapsulant and the different substrates of a PV mo ...

For crystalline-silicon solar cells, voltages close to the theoretical limit are nowadays readily achievable when using passivating contacts. Conversely, maximal current generation requires the integration of the electron and hole contacts at the back of t ...

Silicon heterojunction (SHJ) solar cell efficiencies are limited by parasitic absorption from the hydrogenated amorphous silicon (a-Si:H) front contact, but this may be mitigated by selecting an alternative carrier selective contact material with a wider b ...

Tandem solar cells constructed from a crystalline silicon (c-Si) bottom cell and a low-cost top cell offer a promising way to ensure long-term price reductions of photovoltaic modules. We present a four-terminal tandem solar cell consisting of a methyl amm ...

The high-efficiency silicon heterojunction (SHJ) technology is now perceived mature enough to enter the Giga-Watt manufacturing scale with several players around the globe. The growth of the SHJ technology requires confidence from manufacturers, investors, ...

We investigate the impact of guided modes on the absorption enhancement in solar cells. By considering a dielectric thin film, we show that the absorption can be enhanced beyond the previous predictions even after averaging over wide wavelength ranges.

This book chapter presents an overview of thin-film silicon (both amorphous and microcrystalline) technology and its application to the fabrication of tandem and multiple-junction solar cells. It reviews the material relevant properties for this application and discuss the critical points for achieving high device efficiency. The state-of-the-art, current limitations and prospective concepts are discussed in details.

Perovskite/silicon tandem solar cells have reached efﬁciencies above 25% in just about three years of development, mostly driven by the rapid progress made in the perovskite solar cell research ﬁeld. This review aims to give an overview of the achievements ...

Recent studies showed that SHJ solar cells can be prone to PID when encapsulated with a low volume resistivity encapsulant, such as ethylene vinyl acetate (EVA). These studies also demonstrated that their degradation mechanism is different from Al-BSF modu ...

This study investigates the impact of the laser-enhanced contact optimization (LECO) process on the long-term reliability of tunnel-oxide passivated contact (TOPCon) solar cells. TOPCon technology, which became the dominant photovoltaic (PV) technology in 2024, faces challenges related to moisture ingress and metallization stability. The research compares the performance of LECO and non-LECO TOPCon cells encapsulated with ethylene vinyl acetate (EVA) and polyolefins (PO) under damp heat (DH) and potential-i

Silicon heterojunction solar cells typically use stacks of hydrogenated intrinsic/doped amorphous silicon layers as carrier selective contacts. However, the use of these layers may cause parasitic optical absorption losses and moderate fill factor (FF) val ...

The present invention relates to a solar cell comprising a heterojunction photoelectric device comprising, a front electrode layer, a back electrode layer comprising a metallic contact layer (300), a light-absorbing silicon layer (1 ) arranged between said ...

Christophe Ballif

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Low noise, low power front end electronics for pixelized TFA sensors

Flexible micromorph tandem a-Si/µc-Si solar cells

Influence of the substrate geometrical parameters on microcrystalline silicon growth for thin-film solar cells

Silane depletion dependent ion bombardment and material quality of microcrystalline silicon deposited by VHF-PECVD

Over 31%-efficient perovskite–TOPCon solar cells enabled by AlOx -based hydrogenation and front sub-micron texturing

ZnO Transparent conductive oxide for thin film silicon solar cells

Versatile thin-film photovoltaic laser scribing system

Compressive-shear adhesion characterization of polyvinyl-butyral and ethylene-vinyl acetate at different curing times before and after exposure to damp-heat conditions

Simple processing of back-contacted silicon heterojunction solar cells using selective-area crystalline growth

Evaluating Materials Design Parameters of Hole-Selective Contacts for Silicon Heterojunction Solar Cells

Editorial to the proceedings of the 10th international conference on crystalline silicon photovoltaics

Organic-inorganic halide perovskite/crystalline silicon four-terminal tandem solar cells

Long-term performance and reliability of silicon heterojunction solar modules

Limit of absorption enhancement in solar cells with guided modes

Tandem and Multiple-junction Devices Based on Thin-film Silicon Technology

Perovskite/silicon tandem solar cells: marriage of convenience or true love story? - An overview

Encapsulant Selection for PID Resistant Modules Made with Heterojunction Solar Cells

Assessing the LECO Process: Its Impact on TOPCon Solar Cell and Module Reliability

Nanocrystalline Silicon Carrier Collectors for Silicon Heterojunction Solar Cells and Impact on Low-Temperature Device Characteristics

Silicon heterojunction solar cells and methods of manufacture