SPLTRAK Abstract Submission
Nanoabsorbers for Semitransparent Photovoltaics  
Maximilian Götz-Köhler, Nils Neugebohrn, Norbert Osterthun, Hosni Meddeb, Kai Gehrke, Martin Vehse
German Aerospace Center (DLR) Institute of Networked Energy Systems, Oldenburg, Germany

Semitransparent solar cells based on ultrathin absorbers that allow partial transmission of light are attracting interest due to their promising applications in PV windows. To achieve high transmission of light with simultaneous high photocurrent generation, the materials of the solar cell stack have to be adjusted to each other concerning their response to visible light as well as their optical resonances arising from interference phenomena. Here, we analyze the influence of the refractive index and the thickness of different deeply subwavelength inorganic and organic nanoabsorber layers on the limits of transparency, absorption and spectral light utilization efficiency (sLUE). The results suggest, that for ultra-thin absorber configurations (5 nm), a combination of high real and imaginary parts of the refractive index such as in amorphous germanium might reach the highest sLUE. A detailed analysis including spectral shaping of transmitted light to achieve color neutrality and realized transparent nanoabsorber solar cells will be presented in the extended study.