Solar PV technology trends: A technology shift towards N-type cells

Solar energy is rapidly becoming an important source of electricity around the world, and advancements in solar cell technology are driving the industry forward. One notable trend over the last decade has been the shift from P-type solar cells to N-type solar cells. In this article, we’ll explore this trend and discuss the benefits and potential risks associated with N-type cells.

P-type solar cells have been the industry standard for decades, but N-type solar cells are gaining in popularity due to their increased efficiency and other benefits. One of the main advantages of N-type cells is their higher charge carrier lifetime, which allows them to capture more sunlight and convert it into electricity. They also have an improved temperature coefficient, which means they maintain their efficiency better at higher temperatures than P-type cells. Additionally, N-type cells are less sensitive to metallic impurities in the silicon, which can reduce their efficiency.

Another benefit of N-type cells is that they exhibit reduced light-induced degradation (LID). This is because boron-oxygen defects that cause LID are eliminated with N-type doping using phosphorous. N-type cells also show reduced light and elevated temperature-induced degradation (LeTID), which is likely due to reduced hydrogen content in these cells.

However, there are potential risks associated with N-type cells as well. The complexity and purity of N-type cells can increase their sensitivities to a range of factors, including impurities in the bulk wafer, UV-LID, and degradation of ultrathin layers. Additionally, different cell architectures like TOPCon, PERT, and PERC can exhibit different potential induced degradation (PID) trends, which can impact their long-term performance. There is also a risk of lower reliability from new market entrants, as extended cell reliability testing may not yet be in place.

Another potential downside of N-type cells is their higher cost due to the higher silver content in their contacts. Copper is being explored as a replacement for silver, but it could introduce new reliability issues. Despite these potential risks, the benefits of N-type cells have led to their increased use in the industry.

In summary, the shift towards N-type solar cells has been driven by their increased efficiency, improved temperature coefficient, and reduced sensitivity to metallic impurities. They also exhibit reduced LID and LeTID. However, their complexity and sensitivity to certain factors, as well as their higher cost, must be carefully considered. As the industry continues to evolve, it will be interesting to see how N-type cells continue to impact the solar market.

Here is a summary of the benefits and risks associated with N-type cells: