The hybrid BC battery technology has become increasingly mature, and BC devices will be popular

     BC battery is a general term for back electrode contact battery, and BC is the abbreviation for Back Contact, also known as

IBC battery.

     1. What is BC battery

     Silicon solar cells, whether P-type or N-type, are made by turning silicon wafers into PN nodes and generating electricity

through the photovoltaic effect of the PN nodes. The most traditional approach is to make one side of the silicon wafer into the

P region, which is the positive electrode, and the other side into the N region, which is the negative electrode. Then, lead the

wires out from the positive and negative electrodes to generate electricity. These wires are welded with very thin silver paste,

also known as grid lines, which are the grid silver lines we see on the surface of photovoltaic modules. Grid lines are present on

both the front and back sides of the battery cell, and those on the front side can block some of the cell surface, reducing the

illuminated area and affecting power generation efficiency.

     The biggest feature of BC batteries is that they have no grid lines on the front, and there is no reflection loss when exposed

to light. They have significant advantages in terms of power generation. Based on verification in the Henan and Hebei regions,

their single watt power generation is about 2% -3% higher than TOPCON. Due to the absence of grid lines on the front of BC

batteries, the product has a beautiful appearance and is suitable for household and commercial roof use scenarios, which is

beneficial for promotion in the distributed market.

     2. Advantages of BC batteries

     The back of BC batteries is no longer a simple N or P region, but a cross finger shaped arrangement of P and N regions is

prepared on the back of the battery, which can have both positive and negative electrodes. Thanks to this structure, all the grid

lines can be completely welded to the back of the battery cell. It not only improves power generation efficiency but also

enhances the aesthetic appearance of the front.

     3. Hybrid BC battery

     The efficiency of hybrid BC cells is over 1.5% higher than that of heterojunction (HJT) cells, and its combination with semi

transparent perovskite cells further enhances the conversion efficiency of stacked cells. The perovskite/hybrid BC four terminal

stacked cell has the following advantages:

     1) High conversion efficiency: Perovskite/hybrid BC four terminal stacked cells utilize the advantages of perovskite cells and

hybrid BC cells, and avoid the limitations of current matching pair performance, achieving maximum utilization and conversion

efficiency of solar light, thereby achieving higher battery conversion efficiency.

     2) Simple process: Perovskite/hybrid BC four terminal stacked cells only rely on optical coupling, without considering the

compatibility issues caused by current matching between the top and bottom cells, making the process relatively simple.

     3) Production line compatibility: The combination of perovskite cell production line and silicon-based BC production line can

be used for the preparation of the four terminal stack without the need for separate modification of the existing production line.

     4. BC technology is becoming increasingly mature

     The hybrid BC battery technology has become increasingly mature, and its combination with perovskite cells will create

higher battery conversion efficiency. I believe that in the near future, perovskite/hybrid BC stacked batteries will achieve a

conversion efficiency of over 35%!

     Overall, BC batteries will become the absolute mainstream of crystalline silicon batteries in the future.