Herein, we investigate the process–structure–properties relationships of in situ phosphorus (P)‐doped polycrystalline silicon (poly‐Si) films by atmospheric pressure chemical vapor deposition (APCVD) for fabricating poly‐Si passivating, electron selective contacts. This high‐throughput in‐line APCVD technique enables to achieve a low‐cost, simple manufacturing process for crystalline silicon (c‐Si) solar cells featuring poly‐Si passivating contact by excluding the need for vacuum/plasma environment, and additional post‐deposition doping steps. A thin layer of this P‐doped poly‐Si is deposited on an ultrathin (1.5 nm) silicon oxide (SiO x ) coated c‐Si substrate to fabricate the passivating contact. This is followed by various post‐deposition treatments, including a high‐temperature annealing step and hydrogenation process. The poly‐Si films are characterized to achieve a better understanding of the impacts of deposition process conditions and post‐deposition treatments on the microstructure, electrical conductivity, passivation quality, and carrier selectivity of the contacts which assists to identify the optimal process conditions. In this work, the optimized annealing process with post‐hydrogenation yields passivating contact with a saturation current density (J 0) of 3 fA cm−2 and an implied open‐circuit voltage (iV OC) of 712 mV on planar c‐Si wafer. Junction resistivity values ranging from 50 to 260 mΩ cm2 are realized for the poly‐Si contacts processed in the optimal annealing condition.

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) 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 ) of ≈717 mV after annealing without any additional hydrogenation process. Saturation current density (J ) of ≈18 fA cm−2 is recorded for this contact. Contact resistivity () of ≈50 mΩ·cm−2 and junction resistivity of ≈0.24 Ω·cm−2 are realized with e-beam evaporated aluminium (Al) metal contact.

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