Publications by Christophe Ballif

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Multi-junction photovoltaic devices include two or more component sub-cells which are electrically interconnected in series. At any power point, the current output of the total device is limited by the sub-cell with the smallest current density. Therefore, ...

We investigate the contact resistivity of p-type passivating contacts for silicon solar cells. Our contact structures are compatible with firing, a rapid annealing process similar to the one used for sintering of the screen-printed metallisation in solar c ...

Infrared light management is crucial to maximize the optical performance of crystalline Si-based single junction and tandem solar cells. For this end, a low refractive index dielectric is typically inserted under the rear metal and an electrical contact is ...

In amorphous/crystalline silicon heterojunction solar cells, optical losses can be mitigated by replacing the amorphous silicon films by wider bandgap amorphous silicon oxide layers. In this article, we use stacks of intrinsic amorphous silicon and amorpho ...

We study amorphous silicon-germanium (a-SiGe:H) as intrinsic absorber material for thin-film silicon-based triple and quadruple junction solar cells. First, we present the development of a-SiGe:H single junction devices, in particular the Ge-content gradin ...

Silicon heterojunction (SHJ)-solar modules-when encapsulated with ethylene vinyl acetate (EVA)-are known to be extremely sensitive to water ingress. The reason for this is, however, not clear. Here, we explain the root causes of this degradation mechanism ...

High temperature passivating contacts for c-Si based solar cells are intensively studied because of their potential in boosting solar cell efficiency while being compatible with industrial processes at high temperatures. In this work, the hydrogenation mec ...

Microcrystalline growth regimes and solar cells obtained in different pressure and silane depletion conditions are studied in a large area KAI-S plasma reactor. The microcrystalline material quality is systematically investigated by Fourier Transform Photo ...

The emergence of bifacial photovoltaics as a serious option for large-scale power generation makes the accuracy of the in-situ estimation of ground surface albedo increasingly critical. Recent studies have evaluated the performance of different models but ...

Microchannel plates based on amorphous silicon have the inherent capability to overcome the existing spatial and temporal resolution limitations of single photon detectors. A Monte Carlo model-based study is presented here that serves to exploit their full ...

We compare the performance of two back reflector designs on the optoelectrical properties of microcrystalline silicon solar cells. The first one consists of a 5-mu m-thick low-pressure chemical vapor deposition (LPCVD)-ZnO electrode combined with a white s ...

Bisphenol A polycarbonate (PC), a lightweight and impact-resistant glass substitute widely used in structural and optical applications, suffers from hydrolytic degradation under heat and humidity, limiting its long-term outdoor reliability. In this study, the hydrolysis of PC under neutral and acetic acid conditions was systematically investigated via accelerated aging at a controlled temperature, humidity, and acetic acid concentration. Mechanical degradation was assessed by tensile testing, whereas molecu

We study the interaction of electromagnetic waves in layered media with textured interfaces. Experimental results of a solar cell grown on a sinusoidal back reflector are compared with a theoretical model using an expansion into diffraction modes. We assum ...

The TISO-10-kW plant, installed in Lugano (Switzerland) in 1982, is the first grid-connected PV plant in Europe. In a joint publication (part 1), we presented the results of the electrical characterization performed in 2017-after 35 years of operation-of t ...

Perovskite solar cells (PSCs) show great promise due to their high efficiency and low manufacturing costs, yet they encounter notable challenges such as optical losses and stability issues, mainly due to high surface reflection and degradation from UV irra ...

We study absorption enhancement by light scattering at periodically textured interfaces in thin film silicon solar cells. We show that the periodicity establishes resonant coupling to propagating waveguide modes. Ideally, such modes propagate in the high i ...

The Swiss energy transition, characterized by the nuclear phase-out, relies mainly on the integration of solar photovoltaic (PV), mostly because wind technology faces challenges in local public acceptance. This study aims to analyse Swiss PV and wind gener ...

Developing efficient, stable, and cost-effective photosystems to split water into hydrogen and oxygen using sunlight is of paramount importance for future production of fuels and chemicals from renewable sources. However, the high cost of current systems l ...

In this work, we present the development of passivating contacts based on thin interfacial oxide/doped polysilicon for two side contacted c-Si solar cells. In the first part, we discuss our layer optimization towards direct metallisation, using firing thro ...

Photovoltaic electricity has already proven its ability to compete with other well established technologies for energy production. The abundant and non-toxic raw materials, the yearly increasing efficiency as well as the production cost of silicon thin-film solar cells getting lower and lower make this technology always more interesting for a wide spread use. Beside the functional features, the size, colour and glass texture of a PV module determine its appearance and aesthetics. In order to be more complia

Christophe Ballif

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Optimized short-circuit current mismatch in multi-junction solar cells

Contributions to the contact resistivity in fired tunnel-oxide passivating contacts for crystalline silicon solar cells

Self-Aligned Silica Nanoparticle Rear Reflectors for Single-Junction Si and Perovskite-Si Tandem Solar Cells

Amorphous silicon oxide window layers for high-efficiency silicon heterojunction solar cells

Amorphous silicon-germanium for triple and quadruple junction thin-film silicon based solar cells

A comprehensive physical model for the sensitivity of silicon heterojunction photovoltaic modules to water ingress

Analysis of hydrogen distribution and migration in fired passivating contacts (FPC)

Low power high growth rate deposition of microcrystalline silicon

Calibration of ground surface albedo models

Single photon detection with amorphous silicon-based microchannel plates: A Monte Carlo model

Silver versus white sheet as a back reflector for microcrystalline silicon solar cells deposited on LPCVD-ZnO electrodes of various textures

Impact of Acetic Acid on the Hydrolysis Kinetics of Polycarbonate

Resonant Absorption Enhancement in Solar Cells With Periodically Textured Interfaces

35 years of photovoltaics: Analysis of the TISO-10-kW solar plant, lessons learnt in safety and performance-Part 2

Improving the photo-stability of triple cation perovskite solar cells using chromophore-infused optically transparent Pectin/polymethyl methacrylate composite

Resonances and absorption enhancement in thin film silicon solar cells with periodic interface texture

Embracing wind power in the solar PV-dominated Swiss landscape

Solar Water Splitting with Perovskite/Silicon Tandem Cell and TiC-Supported Pt Nanocluster Electrocatalyst

Localisation of front side passivating contacts for direct metallisation of high-efficiency c-Si solar cells

Efficiency of silicon thin-film photovoltaic modules with a front coloured glass