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The boron emitter formation for tunnel oxide passivated contact (TOPCon) solar cells faces higher costs compared to the POCl 3 diffusion for passivated emitter and rear (PERC) solar cells due to the requirement for higher temperatures and longer process times. This work presents an alternative energy-efficient and low cost of ownership boron diffusion approach for TOPCon solar cells, enabling a highly increased throughput compared to the typically used gas phase diffusion. We use an atmospheric pressure chemical vapor deposition borosilicate glass layer as the boron dopant source and combine it with a subsequent thermal anneal in a quartz tube furnace for dopant drive-in. Here, we either use a conventional single-slot quartz boat configuration, or, for highly increased throughput, a vertical wafer stack configuration with the wafer surfaces in direct contact with each other. We show that this approach yields an emitter doping profile comparable to the state-of-the-art gas phase diffusion with sufficient uniformity across the wafer area. We further investigate the emitter dark saturation current densities j 0e as well as the energy conversion efficiency of TOPCon solar cells fabricated for each configuration and compare the results to those of a BBr 3 reference process. These solar cells achieve energy conversion efficiencies exceeding 23% for the stack diffusion approach. Additionally, we demonstrate a potential reduction in both the cost of ownership and the specific electricity consumption of the presented approach.Index Terms-Atmospheric pressure chemical vapor deposition (APCVD), borosilicate glass (BSG), BBr 3 , boron diffusion, high throughput, stack diffusion, tunnel oxide passivated contact (TOPCon). I. INTRODUCTIONP ASSIVATED contacts on n-type monocrystalline silicon wafers are widely seen as the forthcoming cell technology. Within this decade, this technology is expected to gain a Manuscript

Oxygen precipitates are among the most detrimental oxygen‐related silicon bulk defects formed during solar cell manufacturing. These defects are formed only during high‐temperature processes, impeding an identification of prone materials during incoming inspection. Moreover, the prediction of oxygen‐precipitate‐related bulk charge carrier recombination currently requires advanced numerical simulation. This work presents an easily implementable model to predict the bulk carrier lifetime limit, using the temperature–time profile of a high‐temperature process as well as the material properties as the input data. In addition to published analytical descriptions of oxygen precipitation, an empirical description of the retarded growth of small precipitates is included. Furthermore, the time‐lag in nucleation is explicitly considered, which is, to our knowledge, not implemented in oxygen precipitation modeling so far. The calibration of the two free parameters of the model is achieved using the experimental data of 19 different thermal process combinations performed using a single material. This results in a good agreement not only for the material used for calibration but also for other silicon materials. A validation based on passivated emitter and rear cells as well as on test structures confirms the ability of the model to predict bulk carrier lifetimes after solar cell processing.