Publications by Andrea Feltrin

Microcrystalline and micromorph device improvements through combined plasma and material characterization techniques

Christophe Ballif, Benjamin Strahm, Andrea Feltrin, Gaetano Parascandolo, Grégory Bugnon

Hydrogenated microcrystalline silicon (μc-Si:H) growth by very high frequency plasma-enhanced chemical vapor deposition (VHF-PECVD) is studied in an industrial-type parallel plate KAI reactor. Combined plasma and material characterization techniques allow ...

Elsevier B.V Amsterdam2011

High-rate deposition of microcrystalline silicon in a large-area PECVD reactor and integration in tandem solar cells

Christophe Ballif, Andrea Feltrin, Gaetano Parascandolo, Grégory Bugnon

We study the high-rate deposition of microcrystalline silicon in a large-area plasma-enhanced chemical-vapor-deposition (PECVD) reactor operated at 40.68 MHz, in the little-explored process conditions of high-pressure and high-silane concentration and depl ...

2010

ZnO Transparent conductive oxide for thin film silicon solar cells

Christophe Ballif, Sylvie Faÿ, Thomas Söderström, Andrea Feltrin, Peter Cuony, Sylvain Nicolay, Grégory Bugnon, Franz-Josef Haug, Mathieu Gérard Boccard, Matthieu Despeisse

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 ...

Spie-Int Soc Optical Engineering, Po Box 10, Bellingham, Wa 98227-0010 Usa2010

Resistive interlayer for improved performance of thin film silicon solar cells on highly textured substrate

Christophe Ballif, Andrea Feltrin, Peter Cuony, Grégory Bugnon, Adrian Billet, Matthieu Despeisse, Michael Elias Stückelberger

The deposition of thin-film silicon solar cells on highly textured substrates results in improved light trapping in the cell. However, the growth of silicon layers on rough substrates can often lead to undesired current drains, degrading performance and re ...

AIP American Institute of Physics2010

Input silane concentration effect on the a-Si:H to uc-Si:H transition width

Christophe Ballif, Christoph Hollenstein, Fanny Sculati-Meillaud, Benjamin Strahm, Andrea Feltrin, Grégory Bugnon

In this work the microstructure transition width from amorphous to microcrystalline silicon is discussed. It is shown that the width of the transition depends on the input silane concentration level and indirectly on the silane depletion level. The higher ...

2010

Research and developments in thin film silicon photovoltaics

Christophe Ballif, Sylvie Faÿ, Martin Python, Thomas Söderström, Andrea Feltrin, Gaetano Parascandolo, Grégory Bugnon, Franz-Josef Haug, Matthieu Despeisse

The increasing demand for photovoltaic devices and the associated crystalline silicon feedstock demand scenario have led in the past years to the fast growth of the thin film silicon industry. The high potential for cost reduction and the suitability for b ...

2009

Laser applications in thin-film photovoltaics

Christophe Ballif, Benjamin Strahm, Andrea Feltrin

We review laser applications in thin-film photovoltaics (thin-film Si, CdTe, and Cu(In,Ga)Se2 solar cells). Lasers are applied in this growing field to manufacture modules, to monitor Si deposition processes, and to characterize opto-electrical properties ...

Springer Verlag2009

Optical emission spectroscopy to diagnose powder formation in SiH4-H2 discharges

Christophe Ballif, Benjamin Strahm, Andrea Feltrin

Silane and hydrogen discharges are widely used for the deposition of silicon thin film solar cells in large area plasmaenhanced chemical vapor deposition reactors. In the case of microcrystalline silicon thin film solar cells, it is of crucial importance t ...

2009

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

Christophe Ballif, Andrea Feltrin, Grégory Bugnon, Julien Claude Bailat

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 ...

2009

Influence of pressure and silane depletion on microcrystalline silicon material quality and solar cell performance

Christophe Ballif, Andrea Feltrin, Grégory Bugnon, Julien Claude Bailat

Hydrogenated microcrystalline silicon growth by very high frequency plasma-enhanced chemical vapor deposition is investigated in an industrial-type parallel plate R&D KAI (TM) reactor to study the influence of pressure and silane depletion on material qual ...

2009

Limiting factors in the fabrication of microcrystalline silicon solar cells and microcrystalline/amorphous (‘micromorph’) tandems

Christophe Ballif, Arvind Shah, Martin Python, Andrea Feltrin, Grégory Bugnon

This contribution presents the status of amorphous and microcrystalline silicon solar cells on glass, and discusses some material/fabrication factors that presently limit their conversion efficiency. Particular attention is focused on recent results and de ...

2009

Study of the microstructure transition width from amorphous to microcrystalline silicon as a function of the input silane concentration

Christophe Ballif, Christoph Hollenstein, Benjamin Strahm, Andrea Feltrin, Grégory Bugnon

Amorphous and microcrystalline silicon have been proven to be very interesting for low cost thin film photovoltaic devices. Usually these two materials are deposited using the same large area plasma-enhanced chemical vapor deposition reactors from silane a ...

2009

Development of Micromorph Cells in Large-Area Industrial Reactor

Christophe Ballif, Andrea Feltrin, Gaetano Parascandolo, Grégory Bugnon, Adrian Billet, Matthieu Despeisse

The influences of the deposition pressure and silane depletion on the efficiency of single-junction microcrystalline silicon solar cells has been investigated. The efficiency is found to correlate with the ion energy which affects the density of states in ...

2009

Laser-based plasma diagnostics for PECVD of silicon thin films

Christophe Ballif, Benjamin Strahm, Andrea Feltrin

We present two laser systems to monitor plasma conditions in a plasma-enhanced chemical vapor deposition chamber. The first optical system is a high-resolution quantum cascade laser-based infrared absorption spectrometer designed to measure the input silan ...

Ieee Service Center, 445 Hoes Lane, Po Box 1331, Piscataway, Nj 08855-1331 Usa2009

LATEST DEVELOPMENTS ON MICROMORPH TANDEM CELLS AT IMT

Christophe Ballif, Andrea Feltrin, Gaetano Parascandolo, Grégory Bugnon, Matthieu Despeisse

The latest developments on micromorph tandem cells in small area laboratory and large area industrial PE-CVD systems are reviewed. We report on a 13.3% initial efficiency micromorph tandem cell deposited in our small area system. The development of an in-s ...

2009

Conducting two-phase silicon oxide layers for thin-film silicon solar cells

Christophe Ballif, Andrea Feltrin, Julien Claude Bailat

We present optical properties and microstructure analyses of hydrogenated silicon suboxide layers containing silicon nanocrystals (nc-SiOx:H). This material is especially adapted for the use as intermediate reflecting layer (IRL) in micromorph silicon tand ...

2009

Infrared laser-based monitoring of the silane dissociation during deposition of silicon thin films

Christophe Ballif, Andrea Feltrin

The silane dissociation efficiency, or depletion fraction, is an important plasma parameter by means of which the film growth rate and the amorphous-to-microcrystalline silicon transition regime can be monitored in situ. In this letter we implement a homeb ...

AIP American Institute of Physics2009

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

Christophe Ballif, Andrea Feltrin, Grégory Bugnon

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 ...

2008

Low power high growth rate deposition of microcrystalline silicon

Christophe Ballif, Andrea Feltrin, Grégory Bugnon, Julien Claude Bailat

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 ...

2008

Influence of ion bombardment on microcrystalline silicon material quality and solar cell performances

Christophe Ballif, Fanny Sculati-Meillaud, Andrea Feltrin, Grégory Bugnon, Julien Claude Bailat

Microcrystalline hydrogenated silicon growth with VHF-PECVD was examined in an industrial type parallel plate KAITM reactor. The influence of pressure on material quality was studied in single junction solar cells. Solar cells with their intrinsic layer pr ...

2008