Title:	Newly Developed High-Throughput PECVD Source and Platform for Industrial Production of PERC and TOPCon Silicon Solar Cells
Author(s):	F. May, T. Dippell, M. Dörr, P. Wohlfart
Topic:	Silicon Materials and Cells
Subtopic:	Manufacturing & Production of Si Cells
Event:	37th European Photovoltaic Solar Energy Conference and Exhibition
Session:	2CV.1.50
ISBN:	3-936338-73-6
Price:	0,00 EUR
Document(s):	poster

Abstract/Summary:

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Passivated emitter and rear cells (PERC) are established as standard product in crystalline silicon based photovoltaic (PV) cell manufacturing. The PERC process flow was a non-disruptive technology upgrade to existing Al BSF cell production lines. One decisive additional process steps is the deposition of a rear passivation layer stack of aluminum oxide (AlOx) and silicon nitride (SiNy) by plasma enhanced chemical vapor deposition (PECVD) either in-line or in a batch reactor. With the potential to reach conversion efficiencies of 23 % [1] and even more after transition to bifacial cell architectures, PERC are the most suitable candidate to bridge the efficiency range towards 25 % before charge carrier selective cell concepts with passivated contacts most likely will take over. The PV industry is currently introducing passivating contacts cells into pilot production lines. A record efficiency of 24.58 % has been already demonstrated with an industrial n-type solar cell [2]. However, current approaches, such as applying LPCVD deposition techniques for contact formation, are not sufficient to be introduced into mainstream manufacturing due to increased process complexity and cost e.g. due to additionally required masking and/or single-sided etching processes. Using a newly developed high-rate PECVD technology, which enables the strictly one-sided deposition of doped silicon layers without wrap-around, leads to a significant reduction of the complexity of TOPCon production. Recently, SINGULUS TECHNOLOGIES has developed a new inline PECVD tool with linear plasma sources to apply dielectric passivation layers for the mass production of PERC and TOPCon cells, which is already prepared to deposit doped silicon layers for solar cells with passivated contacts. This tool and the newly developed high-rate plasma sources for PECVD represent an extension of the universal inline vacuum deposition platform GENERIS (TM). Results of the application of this machine for magnetron sputtered TCO-layers for industrial production of heterojunction silicon solar cells have already been presented in previous publications [3], [4]. Due to a coating width of 8 wafer tracks at dynamic deposition rates between 60 and 150 nm x m/min, the system is designed for a throughput of up to 8000 wafers/h with a reduced number of plasma sources, resulting in a low-maintenance system with an operating time of about 95%. The coating can be applied on both wafer sides in a freely configurable sequence, thus providing a universal tool for the deposition of AlOx, SiNx, SiOy SiOxNy for PERC and TOPCon cells as well as a-Si / poly-Si layers on high efficiency cell architectures with passivated contacts. In this contribution we will present the machine layout, data on the plasma sources as well as layer and cell properties including layer thickness, homogeneity, deposition rates, charge carrier lifetime, and I-V data of PERC and TOPCon solar cells whose passivation stack, front side anti-reflective and / or poly-Si coatings were produced with the newly developed PECVD technology.