Solar container shell polishing

Can PERC solar cells be polished rear surface?

The resulting industrial-type PERC solar cells with polished rear surface achieve conversion efficiencies up to 19.6% which is comparable to the reference PERC cells which apply a rear protection layer instead of a rear polish process. 2. Experimental We use the RENA InPilot tool for the rear side polishing process.

How does alkaline polishing work?

The alkaline polishing system combines several process steps into a modular system. On the one hand, the emitter layer on the rear side of the wafer, which is grown during the diffusion process, will be single-sided isolated from the front and on the other hand, the rear side of the cell is smoothed and prepared for a perfect surface passivation.

How PERC solar cells are processed?

We process PERC solar cells with cleaning sequence 2 in combination with both 45 and 60 phosphorus diffusions as well as PERC cells with cleaning sequence 3 and a 60 Ohm/sq. diffusion. The rear side polishing removal is 2.5 μm for all cells. The resulting IV data are shown in figure 4. The eaning sequence 2 achieves an efficiency of 19.0%.

What is the best PERC polishing process?

Our currently best-performing PERC polishing process applies a 45 phosphorus diffusion, 2.5 μm rear polishing removal and cleaning sequence 1 (NH 4 OH/HCl, RCA) resulting in 19.6% conversion efficiency which is comparable to our reference PERC process.

What is a solarfold photovoltaic container?

The Solarfold photovoltaic container can be used anywhere and is characterized by its flexible and lightweight substructure. The semi-automatic electric drive brings the mobile photovoltaic system over a length of almost 130 meters quickly and without effort into operation in a very short time.

How does wet polishing affect etching?

The wet polishing chemistry forms a gas phase which can lead to etching of the front wafer surface, however with much lower etch rates compared to the rear polishing etch rates. To further reduce etching from the gas phase we modify the polishing recipe in order to reduce the reactivity of the gas phase.