Project: High-efficiency PERT and IBC cell development focussing on paste and CVD optimization for longterm stability

Acronym	HEAVENLY (Reference Number: 45)
Duration	01/02/2018 - 31/01/2021
Project Topic	This project aims to develop optimized contact formation techniques via the design of new screen-printing pastes and CVD (Chemical Vapour Deposition) multi-functional layers for highly efficient PERT (Passivated Emitter Rear Totally diffused) solar cell architectures and investigate their influence on solar cell characteristics. Increasing solar cell efficiency without a significant cost penalty is key to the growth of solar energy uptake. New industry designs are focusing on the cell's rear side, concentrating on both passivating the rear surface and modifying the metallisation process. Significant gains have come from the PERC (Passivated Emitter and Rear Cell) architecture but PERT cells have the advantages of suffering less from long term degradation. They are also more suitable for bifacial systems potentially increasing power output further. This project will use a PERT solar cell design to evaluate silver (Ag) pastes in functional interaction with multi-purpose CVD layers. p- and n-type mono-crystalline Si substrates will be tested and contact formation will be investigated and optimized. Cell designs will allow for emitter co-diffusion capable of low-cost processing for development of screen-printing pastes and CVD passivation layers for p+ or n+ doped regions. In a later stage the possibility for future gain of the paste and CVD layer approach shall be tested on IBC (Interdigitated Back-Contact) cell designs as proof of principle of our findings. The influence of contact formation on cell parameters will be thoroughly investigated. Of special interest is the influence of the contacting scheme and paste composition on the charge carrier lifetime and interactions of the paste with the CVD layers. Both phenomena have already been identified as important aspects in earlier work. Furthermore, degradation effects under solar cell operating conditions will be investigated. IP protection and commercial sales will be sought from the results of the project.
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Network	SOLAR-ERA.NET Cofund
Call	SOLAR-ERA.NET Cofund

Project partner

Number	Name	Role	Country
1	Johnson Matthey Technology centre	Coordinator	United Kingdom
2	University of Konstanz	Partner	Germany
3	Schmid Group	Partner	Germany