Selective etching for Advanced TOPCON & IBC

The ADE process meets the selective etching requirements of upcoming "Advanced TOPCON" solar cell architectures and IBC.

Extract from: Photovoltaic device innovation for a solar future - https://doi.org/10.1016/j.device.2023.100013

"The latest advance in silicon solar cell technology includes passivating contacts with polysilicon and SiO2. TOPCon technology,10 using an n-type silicon substrate, features an emitter formed with a front boron diffusion, while the rear contact is a 1.5 nm tunneling oxide topped with phosphorous-doped polysilicon, which provides a well-passivated BSF (Figure 1E).

TOPCon cells have reached efficiencies up to 25.8% in the laboratory and average 24.5% in production. TOPCon technology, with a market share of 21% in 2023, is predicted to overcome PERC production by 2025 and is likely to become the technology of choice for new-cell manufacturing in the US. TOPCon is a ‘‘high-temperature’’ passivating contact technology and does not have drastic temperature restrictions for contact firing and module assembly compared with HJT cells. [...]

Crystalline silicon devices are approaching the single-junction theoretical maximum efficiency of 29.4% limited by AugerMeitner recombination. Research is still needed to develop high-temperature, selective area passivating contacts on both sides of the cell (advanced TOPCon [Figure 1F]), [...] and to combine the latest HJT or TOPCon technologies with an IBC structure, which could reach an ultimate practical efficiency of 28% possibly as soon as 2025"