Epitaxial Si films carried by thick polycrystalline Si as a drop-in replacement for conventional Si wafers

Abstract

We demonstrate the fabrication wafer equivalent from the gas phase. The demonstrators are 160 µm thick and 9×9 cm 2 in size. They consists of a type monocrystalline epitaxial layer that is carried deposited, 130 µm-thick, p + -type polycrystalline layer in between the epitaxial Si and the polyrear side of the cell and functions as a reflector oxide make the contact to the base and form a PERL side. The wafer bow is (0.3±0.2 mm). The wafer oriented. Optical analysis demonstrates corresponding to a short circuit current density of ( mA/cm 2 from a 22.6 µm-thick epitaxial layer when random pyramids. Small p-type demonstrator solar cells a base saturation current density of (111±20) fA/cm from a quantum efficiency measurement. The (PolCa) wafer equivalent shortcuts the conventional wafer production process, since it avoids crunching and melting of the poly-Si, growing of the ingot and sawing of the wafers.