Phosphorus-Doped Polysilicon Passivating Contacts Deposited By Atmospheric Pressure Chemical Vapor Deposition

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 (SiOx) passivated n-type crystalline silicon (c-Si) followed by an annealing step at around 910 degrees C, which provides solid phase crystallization. The contact shows an excellent surface passivation quality with an effective minority carrier lifetime of approximate to 4.2 ms and an implied open circuit voltage (iV(OC)) of approximate to 717 mV after annealing without any additional hydrogenation process. Saturation current density (J(0)) of approximate to 18 fA cm(-2) is recorded for this contact. Contact resistivity (rho(c)) of approximate to 50 m Omega center dot cm(-2) and junction resistivity of approximate to 0.24 Omega center dot cm(-2) are realized with e-beam evaporated aluminium (Al) metal contact.