Org_Halb_Si_Zelle

Passivierung von Silizium-Solarzellen mit organischen Halbleitermolekülen mit neuem Prozess zur gezielten Layer-Orientierung zur Wirkungsgradsteigerung

01/01/2020 to 30/06/2022

Single-crystalline Silicon wafers are used as substrates, which are the basic components of nowadays high- efficiency solar cells and are provided to us by the Fraunhofer-ISE. First, the surface of the wafer working as back-electrode is coated with an organic film of semiconducting molecules by means of vacuum- deposition: in this way, the surface is passivated from defects. Such coating step is repeated for 10-12 organic semiconducting materials. For each material, the Fraunhofer-ISE evaluates the quality of the surface passivation by means of charge-carrier lifetime measurements. The 2 materials exhibiting the best passivation ability are subsequently employed in passivation layers between back-electrode and basis of the solar cell, at the same time enhancing the absorption of the solar spectrum in the near-infrared range.
Investigation of the optical, morphological, structural, electronic and charge-transport properties of these semiconducting layers is carried out. The parameters for vacuum-deposition of the organic molecules are adjusted in close dependence of the results from these characterizations of functional properties, in order to optimize the efficiency of the solar cells.