Electrodeposition of Silicon onto Graphite

Dense, well‐adherent silicon was successfully deposited at vs. Pt or Ag onto an inexpensive graphite substrate from the molten salt system at . The solute concentration was in the range of 8–14 m/o. Cross‐sectional views through the deposits indicate a nodular or dendritic growth up to several millimeters on top of an underlying coherent layer of 0.2–0.5 mm thick silicon. The polycrystalline silicon has a columnar structure with normal grain size of 250 μm. The impurities detected were Cu, Fe, and Ni at levels less than 0.005%. The room temperature resistivity has been found to be greater than 1Ω cm. The dependence of the electrodeposition parameters on the morphology and the possibility of direct use of electrodeposited polycrystalline silicon in solar cells are discussed.