Clone of What a negative modulus technology like the N-Type brings to the table

As in most sectors, the standard technology on the market is usually the one that reduces manufacturing costs, since it facilitates the democratization of products.  In recent weeks, mainly as a result of the international PV conference and SNEC 2021 exhibition, N-Type technology has gained prominence, and is expected to massively break into the market very soon.

In this series of three articles, we will begin by addressing the main differences between P-Type and N-Type cells. We will then delve into the advantages of N-Type technology, and finish by explaining the types of cells that exist.

What is the difference between P-Type and N-Type?

The silicon used in both P-Type and N-Type cells is identical. They are even obtained through the same manufacturing process, since the wafers are the same. So when do they become N- or P-type cells? Differentiation appears later, when the cell is doped to add electrons or create "holes", thus favoring the circulation of electric current.

P-type silicon is produced by adding atoms such as boron (mainly) or gallium (used by only a few manufacturers), which have one less electron than silicon in their outer energy level.  Boron has one electron less than needed to form bonds with the surrounding silicon atoms, thus creating an electron vacancy or "hole". As a result of this process, its electric charge is positive and it becomes known as type P (due to its positive charge).

In contrast to P-type cells, the silicon in N-type cells is made by including, for example, phosphorus, which has one more electron in its outer energy level (silicon has four electrons and phosphorus has five). The latter bonds with its neighboring silicon atoms, but one electron does not participate in the bond. Instead, it is free to move within the silicon structure, thus favoring the flow of electric current. Recall that the electron has a negative electric charge, which is why the cell is called N-type (negative).

It is important to note that both technologies use a combination of P- and N-type silicon to form the p-n junction to create an electrical circuit. The difference lies in which of the two is the "dominant" or, as it is often called, the base layer. For this reason, P-type cells use boron-doped silicon as a base together with an ultrathin layer of N-type silicon. N-type cells, on the other hand, use a base of N-type silicon with a thin layer of P-type silicon.

Now that we understand how N-type and P-type cells are created, it is appropriate to ask about their advantages. All of this will be discussed in the next article.

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