Optimization of SiAlON Based Electricity Generating Window Coatings Utilizing a Combinatorial Reactive Sputtering Approach
(Room Room 104-B)
30 Apr 19
10:00 AM
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10:20 AM
Tracks:
Heuréka! Post-Deadline Recent Developments
Transparent electricity generating glass is considered as one of the most promising concepts in building-integrated photovoltaics (BIPV) as it has the potential to convert the built environment, that is currently still responsible for 40% of the electricity consumption, into net zero-energy buildings without compromising the aesthetic appeal of the building. Luminescent coatings on glass can harvest energy by absorbing part of the solar spectrum and subsequently re-emitting it towards the edges of the window through total internal reflection where it is converted into electricity by PV cells. Recently, we discovered that coatings based on the elements Al, Si, O and N (SiAlON), applied in the glass industry for resistance and anti-reflection purposes, may serve as a host for a luminescent coating when doped with rare-earth ions such as Eu or Sm. The luminescent emission properties of the dopant strongly depend on the SipAlqOrNs host composition resulting in a wide tuning range of luminescence from blue to red. Although this wide range is beneficial for tuning possibilities, it makes exploring suitable compositions for an energy generating window a time-consuming and daunting task. In this work, we present Combinamagnetron co-sputtering of Si, Al and Eu or Sm in a reactive O2 and/or N2 + Ar atmosphere as a method to produce luminescence coatings with a large composition range. Characterizing these coatings with EDX combined with a novel semi-automated position dependent tunable laser mapping of the luminescence excitation, emission and transmission spectra allows for relating the material composition with luminescent properties. With an increasing O2:N2 reactive sputtering atmosphere and increasing Si:Al ratio in the coating, an emission color shift from red to blue is observed for Eu2+ and a reduction of the 3+ valence state to 2+ for Sm.