Even though the cost of high efficiency cells production is considerably more than standard silicon cells and is typically limited to use in niche industries like solar cars or space applications, all the manufacturers of solar cells are looking for developing and pursuing high efficiency solar cells technologies to be able to provide better products to customers.
Bifacial solar cells are getting more popular in the market. The bifacial cells can absorb light and generate electric energy from both surfaces which can lead to achieving up to 30 % higher yield than conventional cell technologies, if suitably installed in open areas or flat roofs.
What is PERT solar cells technology?
In contrast to standard cells and PERC technologies, which both use the aluminum-alloy BSF, PERT (Passivated Emitter Rear Totally Diffused) cells have a diffused rear surface. That means, with p-PERT the emitter of p-type based wafer is formed with phoshphorus diffusion and BSF is realized with boron doping. PERT cells do not show the considerable light-induced degradation and can be adapted to bifacial cell structure.
PERT solar cells efficiency
High-efficiency passivated emitter, rear totally diffused (PERT) cells demonstrated energy conversion efficiency reaching nearly 25% under standard conditions of AM1.5 spectrum at 25°C. This energy conversion efficiency is the highest ever reported efficiency for a silicon cell which is based on a non-FZ silicon substrate. The PERT cell’s light boron diffusion in the cell structure not only reduced the series resistance of the cell but improved the cell open circuit voltage as well.
Benefits of PERT solar cells Technology
- High efficiency which is achieved by passivation on multi material
- Boron BSF PERT multi cells display no light-induced degradation (LID) unlike PERC cells
- Same ownership cost as for PERC cells
- PERT line can be used for monofacial or bifacial cells as well which leads to high flexibility
Manufacturing of PERT solar cells
Manufacturing of PERT solar cells has many advanced processes and many configurations for optimization of different cells. New smart technologies like APCVD (Atmospheric Pressure Chemical Vapor Deposition) systems are used in manufacturing and produce products with high acceptance for more than 10 years. Also, phosphorus emitter and boron BSF are formed in one thermal cycle with Horizontal Tube Furnace leading to simpler better cycle times.
Since PERT solar cells can also be used in conventional backsheet modules, simple process for reconfiguration of the production line to changeover production of PERT monofacial to bifacial take just hours.