Publications

 


Here you find some recent publications, for an extended list of my work, please have a look at my publication list. Also have a look at recent eBooks on the Apple iTunes Store.


Les publications en français / / / Publikationen in Deutsch.




PV-School in English:
100-Days, A collection of periodic web blog entries statements and articles, facts, and figures, lessons on solar electricity. Available for the iPad, the Kindles and Androids, see here.

  1. Youtube: In this trailer, you see some features of the draft version of an electronic textbook designed for tablet computer iPad. The topic is Plasma Enhanced Chemical Vapour Deposition (PECVD) and stands just as a Demonstration topic to Highlight the possibilities of eLearning. It is an initiative to bring natural science to the digital natives.
    You can have more such topics of the PV-School collection, just ask gomicromorph.com.
    http://www.youtube.com/watch?v=5VUGZbFEYWU


  1. Contribution to the 27th EU PVSEC, September 2012 in Frankfurt: ELEARNING:

    UNDERSTANDING PECVD TOOLS AND PROCESSES FOR THIN-FILM COATINGS

    Abstract: The present work stands as a methodological example in teaching, a meta-paper: the selected topic of study is how to understand empirically the process of plasma enhanced chemical vapor deposition (PECVD). This text is a slightly altered version of the text submitted to the conference proceedings. See the submitted paper in PDF or in EPUB, the corresponding eBook on the iTunes Store, the poster in A4 format PDF.


  1. PECVD, understanding tools and processes: draft version of an interactive tutorial running on the Apple iPad in iBooks. Hint: download the linked file PECVD5.ibooks (47 MB) directly on your iPad and open it in the iBooks App or download the file onto your computer, pass it to iTunes and from the section ‘books’ on the top left pane pass it to the books section (lower left side) of your iPad and sync.
    Available now for free worldwide as download from Apple iBookstore.


  1. Proceedings of the 26th EU-PVSEC 2011, Hamburg. Session ‘PV and Architecture, Experience and Trends in BIPV’: FIRST THREE YEARS OF OPERATION OF AN AMORPHOUS SILICON THIN-FILM BIPV-SYSTEM FROM ERSOL THIN-FILM (BOSCH SOLAR)

    By Luc Feitknecht
    Download the preprint or the copy of the official proceedings
    Abstract: The present paper gives insight into the application of thin-film silicon modules in the example of an alpine roof-integrated 1.5 kWP PV-system connected to the electrical grid. Instead of expensive instrumented laboratory measurements, the data of relatively low-cost standard measurement equipment is interpretation here. The yearly specific yield reaches in average 1065 kWh/kWPeak and a PR of 87% after three years. These measured values are compared with the simulated output values of a PV-simulation program. The summer half-year contributes 79% to the overall yield, the simulation predicts 15% too low the summer yield. The electrical power output in winter is quite low, essentially due to the snow coverage on the modules. Explanations for the inaccuracies of the output prediction of the PV-simulation software are evaluated. Consequences for the architecture of Building Integrated Photovoltaic (BIPV) in climatic regions with snow are discussed.


  1. Accepted for publication for the ICMAT’11 conference, Symposium O: Photovoltaic Materials and Devices (see programme) in Energy Procedia, Volume 15, 2012, Pages 396-402
    Evaluations on Current-matching of Multi-junction Photovoltaics under Outdoor Conditions   Original Research Article
    Download preprint version:
    Evaluations on current-matching of multi-junction photovoltaics under outdoor conditions
    By Luc Feitknecht
    Abstract / get preprint ICMAT11-A-1132_Feitknecht.pdf
    Key differences of precisely measuring currents on wafer based solar cells and multi-junction solar cells are shortly described at the beginning of the paper. In the next section, the impact of precise Standard Test Condition (STC) measurements on the energy-yield prediction by PV-simulation software is reviewed, with special mention of the Staebler-Wronski Effect. Solar modules containing amorphous silicon absorbers perform in moderate latitudes in a cyclic way: hot season with higher output and cool season with lower output. Both, spectral variations of the irradiance as well as temperature rise during irradiance are reported in literature contributing to this cycling behaviour, which finally is not an issue but a feature of this technology. In consequence, a ‘design to geography’ approach is suggested for module manufacturers, allowing for higher energy yields even without considerably increasing nameplate power under STC. Standardisation, which highlights the energy yield in addition to STC nameplate power, is identified as urgently needed. A better understanding of amorphous silicon based multi-junction PV modules can only be gained, if more spectrally resolved data acquisition is performed and evaluated for high and low geographic latitudes. Instead of a ‘static’ temperature coefficient, amorphous silicon modules are better characterised with the ‘effective’ temperature coefficient which can become positive e.g. in building integrated heat-insulating PV-elements.


  1. Microcrystalline Silicon Solar Cells
    By Lukas Feitknecht
    In the presented PhD thesis, the technological aspects of fabricating microcrystalline thin-film silicon solar cells are highlighted: deposition rate, light-trapping, efficiency increase based on plasma coated silicon on opaque substrates and its optimisation on various transparent conductive oxides such as ZnO.


  1. Manufacturing Progress for Amorphous Silicon-Based Solar Cells
    Luc Feitknecht, goMicromorph Ltd.
    Published online in Future Photovoltaics Volume 3, Dec. 2010


  1. The Advantages of Amorphous Silicon
    Luc Feitknecht, University of Applied Sciences of Technology Buchs NTB
    Abstract: Are high efficiency and high deposition rate the keys to the success of thin film silicon solar cells? The early days of thin film silicon are sketched to understand the present situation of this promising technology. Thin films have seen a second boom phase in the last three years, but over the last 15 years, it has rather lost market share. Conversion efficiency of today’s thin film silicon modules are on the edge of 10 percent, and enormous cost-saving potential exists compared to wafer-based solar cells.


  1. Link to FuturePV, Future Photovoltaics, Volume 1, June 2010, Thin Film Photovoltaics:
    http://www.futurepv.com/node/158