Phosphorus-doped polysilicon passivating contacts deposited by atmospheric pressure chemical vapor deposition. (9th July 2021) - Mousumi, Jannatul Ferdous
Abstract: In this work, we present a high quality tunnel oxide passivating, electron-selective contact that is formed using an in-situ phosphorus-doped polycrystalline silicon (poly-Si) layer deposited using an in-line atmospheric pressure chemical vapor deposition (APCVD) process. In-line APCVD is a single-sided deposition process that does not require vacuum systems and is well suited for high volume manufacturing. To fabricate this tunnel oxide passivating contact (TOPCon), we deposit an amorphous silicon (a-Si) layer on silicon oxide (SiO x ) passivated n -type crystalline silicon (c-Si) followed by an annealing step at around 910 ∘ C, which provides solid phase crystallization. The contact shows an excellent surface passivation quality with an effective minority carrier lifetime of ≍4.2 ms and an implied open circuit voltage ( iV OC ) of ≍717 mV after annealing without any additional hydrogenation process. Saturation current density ( J 0 ) of ≍18 fA cm −2 is recorded for this contact. Contact resistivity ( ρ c ) of ≍50 mΩ·cm −2 and junction resistivity of ≍0.24 Ω·cm −2 are realized with e-beam evaporated aluminium (Al) metal contact.