Due to their fascinating optical and electronical properties, nanometer-scaled structures play an important role in solar energy conversion. In our research group at EPFL’s Solar Energy Laboratory LESO-PB, we develop novel micro- and nanostructured smart materials for active and passive solar energy applications being integrated into the building envelope. We focus on thin films, because these allow covering a large surface area with a small quantity of raw material – and we focus on their electronic and optical properties, because these closely interrelated properties are most important for the utilisation of solar energy.
Nanocomposite coatings consist typically of dielectric, semiconductor or metal nanocrystals being embedded in a dielectric matrix. Effective medium theories such as the Bruggeman and the Ping Sheng theories are used to model the dielectric function of nanocomposite materials. Micro- and/or nanostructuring materials can result in very interesting features such as tuneable band-gaps by quantum confinement, adjustable complex dielectric function, enhanced mechanical stability, superhydrophobicity, frequency-selective surfaces FSS, etc. The semiconductor-to-metal transition observed in transition metal oxides with strong electron correlations can be exploited for smart switching coatings.
The scope of envisaged solar energy applications is large. Recent work focuses especially on smart materials, such as thermochromic selective solar absorber coatings for overheating protection of solar thermal systems, and electrochromic coatings for switchable windows. Further applications include novel microstructured glazing with strong seasonal dependence of the solar heat gains, photoluminescent quantum dot solar concentrators for photovoltaic energy conversion, antireflection coatings on solar collector glazing, colored coatings with high solar transmittance for novel glazing of photovoltaic facades, selective solar absorber coatings for thermal solar collectors and thermoelectric power generation, as well as novel insulating glazing with high transmittance for the microwaves of mobile communication.
- Optical coatings on solar glass for photovoltaic modules and solar thermal collectors – development of colored glazing for solar facades and solar roofing
- Solid-ion-conductors for durable electrochromic windows
- Metallic micro-/nanomeshes for transparent conductive layers
- Nanostructured low refractive index materials on solar collector glazing
- Smart selective solar absorber coatings based on reversible semiconductor-to-metal transition
- Optical microstructures for advanced architectural glazing
- Energy efficiency of public transportation
- Frequency-selective surfaces by nanosecond laser-ablation
- Angular dependent optical and thermal properties of advanced architectural glazing
- Highly durable selective solar absorber coatings for solar thermal collectors and electricity generation by concentrated solar power (CSP)
- Quantum dot solar concentrators for building integrated photovoltaics
WO2017134589 (A1) : Coating for optical and electronic applications – Single- or multilayered coating, such as a selective solar absorber coating or a coating being part of an integrated electronic circuit, comprising one or more layers containing germanium (Ge) doped VO2+x, where -0.1 ≤ x ≤ 0.1.
Krammer Anna, Paone Antonio, Schüler Andreas
PCT/IB2017/051952: Solar cooker
Mauree Dasaraden, Schueler Andreas, Diévart Alexandre, Bouvard Olivia
WO 2014045141 A2: Laminated glazing with coloured reflection and high solar transmittance suitable for solar energy systems
Le Caër Hody Virginie, Schüler Andreas (Déposant SwissInso SA)
WO 2014045144 A1: Interference filter with angular independent orange colour of reflection and high solar transmittance, suitable for roof-integration of solar energy systems
www.glassdbase.ch – an independent and comprehensive building glass database set up by University of Basel, Switzerland and now managed by LESO-PB
Bouvard Olivia, Scartezzini Jean-Louis and Schueler Andreas (Dirs.). Coatings with tailored electronic and optical properties for advanced glazing. EPFL Thesis n° 9199 (2019)
Microstructured glazing for daylighting, glare protection, seasonal thermal control and clear view. EPFL PhD thesis, n° 6465 (2015)
A. Paone, J.-L. Scartezzini and A. Schueler (Dirs.). Switchable Selective Absorber Coatings for Overheating Protection of Solar Thermal Collectors. EPFL PhD thesis, n° 5878 (2013)
Développement et optimisation de revêtements minces nanostructurés pour capteurs solaires thermiques et modules photovoltaïques. EPFL PhD thesis, n° 5541 (2012).
RailTech 2019 Innovation Award, Utrecht, to Andreas Schüler, Olivia Bouvard, Luc Burnier, Jérémy Fleury, for Energy efficient windows that transmit telephone signals.
Watt d’Or 2019 “Energy efficient mobility” by Swiss Federal Office of Energy, Andreas Schüler, Olivia Bouvard, Luc Burnier, Jérémy Fleury (as part of a team headed by BLS train company and Basel University), for Nina trains energy efficiency modernisation. Contribution: energy efficient windows transparent to phone signals.
Award winning publications
Jing Gong, André Kostro, Jean-Louis Scartezzini, Andreas Schüler, Feasibility study on a novel daylighting system with embedded micro compound parabolic concentrators (CPCs). Nonimaging Optics: Efficient Design for Illumination and Solar Concentration XV (Vol. 10758, p. 1075807). International Society for Optics and Photonics. Nonimaging optics best paper award – SPIE Optical Engineering & Applications, 2018, 19-20 August 2018, San Diego, CA, USA
Martin Joly, Yan Antonetti, Martin Python, Marina Gonzalez, Thomas Gascou, Jean-Louis Scartezzini, Andreas Schüler, Novel black selective coating for tubular solar absorbers based on a sol-gel method, Solar Energy Journal Best Paper Award 2012-2013
Peter Oelhafen, Andreas Schueler, Nanostructured materials for solar energy conversion, Solar Energy Journal Best Paper in Energy Conversion Award 2005/2006
Wide band-pass FSS with reduced periodicity for energy efficient windows at higher frequenciesApplied Physics A-Materials Science & Processing. 2020-05-13. Vol. 126, num. 6, p. 417. DOI : 10.1007/s00339-020-03547-w.
Thermochromic coatings for overheating protection of solar thermal collectors – Towards industrial implementation – Annual Report 2019
3D Smith charts scattering parameters frequency-dependent orientation analysis and complex-scalar multi-parameter characterization applied to Peano reconfigurable vanadium dioxide inductorsScientific Reports. 2019-12-04. Vol. 9, p. 18346. DOI : 10.1038/s41598-019-54600-5.
Solar cooking potential in Switzerland: Nodal modelling and optimizationSolar Energy. 2019-12-01. Vol. 194, p. 788-803. DOI : 10.1016/j.solener.2019.10.071.
Ni3N as an Active Hydrogen Oxidation Reaction Catalyst in Alkaline MediumAngewandte Chemie-International Edition. 2019-05-27. Vol. 58, num. 22, p. 7445-7449. DOI : 10.1002/anie.201902751.
A Novel Reconfigurable CMOS Compatible Ka Band Bandstop Structure Using Split-Ring Resonators and Vanadium Dioxide (VO2) Phase Change Switches2019-05-07. 2019 IEEE MTT-S International Microwave Symposium (IMS), Boston, June 7-11,2019. p. 865-867. DOI : 10.1109/MWSYM.2019.8701121.
From university to industry – challenges in upscaling optical microstructures for daylight redirection in buildings2019. CISBAT 2019 | Climate Resilient Cities – Energy Efficiency & Renewables in the Digital Era, Lausanne, Switzerland, September 4-6, 2019. p. 012194. DOI : 10.1088/1742-6596/1343/1/012194.
Predicting the thermal performance of thermochromic flat plate solar collectors2019. CISBAT 2019 | Climate Resilient Cities – Energy Efficiency & Renewables in the Digital Era, Lausanne, Switzerland, September 4-6, 2019. p. 012201. DOI : 10.1088/1742-6596/1343/1/012201.
In-situ and post annealing effect on the microstructure and the optical properties of black Cu-Co-Mn oxide spinel coating for Parabolic Trough Collector (PTC) applications2019. CISBAT 2019 | Climate Resilient Cities – Energy Efficiency & Renewables in the Digital Era, Lausanne, Switzerland, September 4-6, 2019. p. 012200. DOI : 10.1088/1742-6596/1343/1/012200.
Novel microwave transparent low emissivity coating for energy-efficient glazing: towards 5G frequencies2019. CISBAT 2019 | Climate Resilient Cities – Energy Efficiency & Renewables in the Digital Era, Lausanne, Switzerland, September 4-6, 2019. p. 012199. DOI : 10.1088/1742-6596/1343/1/012199.
Evaluating the electricity saving potential of electrochromic glazing for cooling and lighting at the scale of the Swiss non-residential national building stock using a Monte Carlo modelEnergy. 2019. Vol. 185, p. 136-147. DOI : 10.1016/j.energy.2019.07.037.
Box-type solar cooker
BAV-RhB Projekt Reduzierung des Heizenergiebedarfs von Bahnfahrzeugen durch eine verbesserte Wärmedämmung der Fahrzeughülle
Towards industrial implementation
A transdisciplinary approach to understand, compute and visualize the city interfaceSwiss Inter- and Transdisciplinarity Day 2018, EPFL, Lausanne (Switzerland), 15th November 2018.
Feasibility study on a novel daylighting system with embedded micro compound parabolic concentrators (CPCs)2018. Conference on Nonimaging Optics – Efficient Design for Illumination and Solar Concentration XV, San Diego, CA, Aug 19-20, 2018. p. 1075807. DOI : 10.1117/12.2320478.
Thermochromic coatings for overheating protection of solar thermal collectors – novel type of doping (TARGET95)
Thermochromic coatings for overheating protection of solar thermal collectors – novel type of doping (TARGET95)
Daylight in the Built EnvironmentScience/AAAS. 2017-11-03. Vol. Changing perspectives on daylight: Science, technology, and culture (Supplement), p. 24-32.
Daylight in the built environmentChanging perspectives on daylight: Science, technology, and culture; Washington, DC: Science/AAAS, 2017. p. 46.
Colored solar façades for buildings2017. CISBAT 2017 International Conference, Lausanne, Switzerland, 6-8 September 2017. p. 175-180. DOI : 10.1016/j.egypro.2017.07.340.
Visual prominence vs architectural sensitivity of solar applications in existing urban areas: an experience with web-shared photos2017. CISBAT 2017 International Conference, Lausanne, Switzerland, 6-8 September 2017. p. 955-960. DOI : 10.1016/j.egypro.2017.07.437.
Development and characterization of electrochromic oxide and ion conductor deposited by reactive magnetron sputtering2017. CISBAT 2017 International Conference, Lausanne, Switzerland, 6-8 September 2017. p. 787-792. DOI : 10.1016/j.egypro.2017.07.397.
Study of Si doped VO2 thin films for solar thermal applications2017. CISBAT 2017 International Conference, Lausanne, Switzerland, 6-8 September 2017. p. 745-750. DOI : 10.1016/j.egypro.2017.07.390.
Dimensional stability analysis of a UV printed polymer microstructure for a novel glazing system2017. CISBAT 2017 International Conference, Lausanne, Switzerland, 6-8 September 2017. p. 763-768. DOI : 10.1016/j.egypro.2017.07.393.
Mobile communication through insulating windows: a new type of low emissivity coating2017. CISBAT 2017 International Conference, Lausanne, Switzerland, 6-8 September 2017. p. 781-786. DOI : 10.1016/j.egypro.2017.07.396.
Shunt capacitive switches based on VO2 metal insulator transition for RF phase shifter applications2017. ESSDERC 2017 – 47th IEEE European Solid-State Device Research Conference (ESSDERC), Leuven, Belgium, 11-14 September 2017. p. 232-235. DOI : 10.1109/ESSDERC.2017.8066634.
Integration of dye solar cells in load- bearing translucent glass fiber- reinforced polymer laminatesJournal of Composite Materials. 2017. Vol. 51, num. 7, p. 939-953. DOI : 10.1177/0021998316656393.
Potential advantages of a multifunctional complex fenestration system with embedded micro-mirrors in daylightingSolar Energy Journal. 2016. Vol. 139, p. 412-425. DOI : 10.1016/j.solener.2016.10.012.
In situ photoelectron spectroscopic characterization of reactively sputtered, doped vanadium oxide thin films2016. 16th European Conference on Applications of Surface and Interface Analysis (ECASIA). p. 440-444. DOI : 10.1002/sia.5989.
Investigation of the metal-insulator transition in VO2 for Electronic Switches with Sub-1mV/Decade Steep Subthreshold Slope2016. 2016 IEEE Silicon Nanoelectronics Workshop (SNW), Honolulu, HI, USA, 12-13 June 2016. p. 180-181. DOI : 10.1109/SNW.2016.7578041.
CFSpro: ray tracing for design and optimization of complex fenestration systems using mixed dimensionality approachJournal of Applied Optics. 2016. Vol. 55, num. 19, p. 5127-5134. DOI : 10.1364/AO.55.005127.
Electrothermal actuation of vanadium dioxide for tunable capacitors and microwave filters with integrated microheatersSensors & Actuators: A. Physical. 2016. Vol. 241, p. 245-253. DOI : 10.1016/j.sna.2016.01.027.
In situ core-level and valence-band photoelectron spectroscopy of reactively sputtered tungsten oxide filmsSurface and Interface Analysis. 2016. Vol. 48, num. 7, p. 660-663. DOI : 10.1002/sia.5927.
Optical and structural analysis of sol-gel derived Cu-Co-Mn-Si oxides for black selective solar nanocomposite multilayered coatingsSolar Energy Materials And Solar Cells. 2015. Vol. 143, p. 573-580. DOI : 10.1016/j.solmat.2015.06.058.
Optically-derived mechanical properties of glass fiber-reinforced polymer laminates for multifunctional load-bearing structuresJournal of Composite Materials. 2015. Vol. 49, num. 28, p. 3539-3556. DOI : 10.1177/0021998314567696.
Structural, electrical and magnetic characterization of in-situ crystallized ZnO:Co thin films synthesized by reactive magnetron sputteringMaterials Chemistry And Physics. 2015. Vol. 161, p. 26-34. DOI : 10.1016/j.matchemphys.2015.04.037.
CMOS-compatible abrupt switches based on VO2 metal-insulator transition2015. Ultimate Integration on Silicon, Bologna, Italy, January 26-28, 2015.
Influence of doping in thermochromic V1−xWxO2 and V1−xAlxO2 thin films: Twice improved doping efficiency in V1−xWxO2Journal of Alloys and Compounds. 2015. Vol. 621, p. 206-211. DOI : 10.1016/j.jallcom.2014.08.264.
Diffuse light transmittance of glass fiber-reinforced polymer laminates for multifunctional load-bearing structuresJournal of Composite Materials. 2014. Vol. 48, num. 29, p. 3621-3636. DOI : 10.1177/0021998313511655.
Total light transmittance of glass fiber-reinforced polymer laminates for multifunctional load-bearing structuresJournal of Composite Materials. 2014. Vol. 48, num. 29, p. 3591-3604. DOI : 10.1177/0021998313511653.
CFSPro: Ray Tracing for Profile Optimisation of Complex Fenestration Systems using mixed dimensionality approachStatus-Seminar «Forschen für den Bau im Kontext von Energie und Umwelt, ETH, Zurich, Switzerland, September 4-5,2014.
Light diffusion in GFRP laminates for building construction2014. CICE2014, The 7th International Conference on FRP Composites in Civil Engineering, Vancouver, Canada, August 20-22, 2014.
Thermal solar collector with VO2 absorber coating and V1-xWxO2 thermochromic glazing – Temperature matching and triggeringSolar Energy. 2014. Vol. 110, p. 151-159. DOI : 10.1016/j.solener.2014.08.033.
Growth optimization of vanadium dioxide films on SiO2/Si substrates2014. 40th Micro and Nano Engineering, Lausanne, Switzerland, September 22-26, 2014.
Reactively sputtered coatings on architectural glazing for coloured active solar thermal façadesEnergy and Buildings. 2014. Vol. 68, p. 764-770. DOI : 10.1016/j.enbuild.2012.12.030.
Selective solar absorber coatings on receiver tubes for CSP – energy-efficient production process by sol-gel dip-coating and subsequent induction heating2014. ISES Solar World Congress, Cancun, Mexico, November 3-7, 2013. p. 487-496.
Mixed-Dimensionality Approach for Advanced Ray Tracing of Lamellar Structures for Daylighting and Thermal Control2013. CISBAT 2013, Lausanne, Switzerland, September 4-6, 2013. p. 1115-1120.
Angular Dependent Solar Gain for Multiple Glazing from Optical and Thermal Data2013. CISBAT 2013, Lausanne, Switzerland, September 4-6, 2013. p. 223-228.
Total Light Transmittance of Glass Fiber-Reinforced Polymer Laminates for Multifunctional Load-Bearing Structures2013. CISBAT 2013, Lausanne, Switzerland, September 4-6, 2013. p. 73-78.
Energy-Efficient Sol-Gel Process for Production of Nanocomposite Absorber Coatings for Tubular Solar Thermal Collectors2013. CISBAT 2013, Lausanne, Switzerland, September 4-6, 2013. p. 11-16.
Novel black selective coating for tubular solar absorbers based on a sol-gel methodSolar Energy. 2013. Vol. 94, p. 233-239. DOI : 10.1016/j.solener.2013.05.009.
Optical and morphological characterisation of low refractive index materials for coatings on solar collector glazingRenewable Energy. 2013. num. 53, p. 27-34. DOI : 10.1016/j.renene.2012.10.052.
Embedded microstructures for daylighting and seasonal thermal control2012. SPIE 2012 International Symposium on Optical Engineering, San Diego, USA, August 13-16, 2012. DOI : 10.1117/12.930476.
New challenges in solar architectural innovation2011. CISBAT 2011, Lausanne, September 14-16.
Towards microstructured glazing for daylighting and thermal control2011. CISBAT 2011, Lausanne, September 14-16. p. 455-460.
Coloured coatings for glazing of active solar thermal façades by reactive magnetron sputtering2011. CISBAT 2011, Lausanne, Switzerland, September 14-16, 2011. p. 31-36.
Air cooling powered by façade integrated coloured opaque solar thermal panels2011. CISBAT 2011, Lausanne, Switzerland, September 14-16, 2011. p. 317-322.
Nanocomposite Coatings for Solar Energy Conversion: Large Opportunities for Small StructuresLecture series at ETHZ, Zurich, May, 19, 2011.
Semiconductor-metal transition in vanadium dioxide based thin films: towards “smart” solar energy materials2010. From Solid State to BioPhysics V, Cavtat, Dubrovnik, Croatia, June 12 – 19, 2010.
Bringing colours to solar collectors: a contribution to an increased building “integrability”2010. Colour & Light in Architectecture, Venice, November 11-12, 2010.
Thermochromic films of VO2:W for smart solar energy applications2009. SPIE Optics & Photonics 2009, San Diego, California, USA, 2-6 August 2009. p. 74100F-74100F-10 (2009). DOI : 10.1117/12.826143.
Solid State Science Special Issue: Symposium A on carbon-based nanostructured composite films Nanomaterials and Nanotechnology E-MRS Spring Meeting 2008Solid State Sciences. 2009. Vol. 11, p. 1737-1737. DOI : 10.1016/j.solidstatesciences.2009.09.013.
Optical selective coating for solar absorbers2009. CISBAT 2009, Lausanne, September 2-3. p. 23-28.
Thermochromic Films of VO2:W for “Smart” Solar Energy Applications2009. CISBAT 2009, Lausanne, September 2-3. p. 29-34.
Modeling the absorption behavior of solar thermal collector coatings utilizing graded a-C:H/TiC layersApplied Optics. 2009. Vol. 48, num. 8, p. 1514-1519. DOI : 10.1364/AO.48.001514.
Monte Carlo simulations of quantum dot solar concentrators: ray tracing based on fluorescence mapping2008. Optics and Photonics 2008, San Diego, August 10-14, 2008. DOI : 10.1117/12.794739.
New: coloured glazings for solar thermal facadesEPFL Research Day 2008, Lausanne, 15 April 2008.
Principles of Monte-Carlo ray-tracing simulations of quantum dot solar concentrators2007. Solar World Congress of the International-Solar-Energy-Society, Beijing, PEOPLES R CHINA, Sep 18-21, 2007. p. 1033-1037.
Facade Integration of Solar Thermal Collectors:A Breakthrough?2007.
Facade Integration of Solar Thermal Collectors: Present and Future2007. CISBAT 2007, Lausanne, 4-5 September 2007. p. 171-176.
Sol-gel deposition and optical characterization of multilayered SiO2/Ti1-xSixO2 coatings on solar collector glassesSolar Energy Materials & Solar Cells. 2006. num. 90, p. 2894-2907. DOI : 10.1016/j.solmat.2006.05.003.
Nanostructured materials for solar energy conversionSolar Energy. 2005. num. 79, p. 110-121. DOI : 10.1016/j.solener.2004.11.004.
Architectural integration of solar thermal collectors: results of a European survey2005. ISES 2005 Solar World Congress, Orlando, USA, August, 6-12.
Thin film multilayer design types for colored glazed thermal solar collectorsSolar Energy Materials & Solar Cells. 2005. num. 89, p. 219-231. DOI : 10.1016/j.solmat.2004.11.015.
Potential of quarterwave interference stacks for colored thermal solar collectorsSolar Energy. 2005. num. 79, p. 122-130. DOI : 10.1016/j.solener.2004.12.008.
Angle-dependent spectrophotometry of Sol-Gel deposited multilayered oxide coatings on solar collector glasses2005. CISBAT 2005, Lausanne, September 28, 2005. p. 227-232.
Towards coloured glazed thermal solar collectorsSolar Energy Materials & Solar Cells. 2004. num. 84, p. 225. DOI : 10.1016/j.solmat.2004.02.042.
Protocol of Measurement Techniques – Colored Solar Collectors
On the feasibility of colored glazed thermal solar collectors based on thin film interference filtersSolar Energy Materials & Solar Cells. 2004. Vol. 84, p. 241-254. DOI : 10.1016/j.solmat.2004.02.045.
Impact of new developments of the integration into facades of solar thermal collectors2004. EUROSUN 2004, Freiburg in Brisgau, June 20-24, 2004. p. 351-357.
Dielectric interference layers for solar thermal collectors2004. EUROSUN 2004, Freiburg in Brisgau, June 20-24, 2004. p. 765-773.
Designing thin film multilayers for colored glazed thermal collectors2004. EUROSUN 2004, Freiburg in Brisgau, Germany, June 20-24, 2004. p. 858-865.