HIT cells, commonly known as heterojunction cells, or crystalline silicon heterojunction solar cells, are a type of technology that deposits amorphous silicon thin films onto crystalline silicon. This technology combines the core advantages of crystalline silicon cells and thin-film cells, and is a popular direction for high-efficiency silicon-based solar cells. Compared to traditional crystalline silicon technology, considering the construction of the amorphous silicon thin film, the crystalline silicon substrate of HIT solar cells undergoes excellent passivation treatment on both the front and back surfaces, resulting in increasingly sophisticated and refined surface passivation processes.
Advantages of heterojunction HIT cells
1. Wide range of applications: HIT batteries play an indispensable role in various economic sectors, including solar panels, urban public transportation, communication equipment, power installation projects, national defense technology, ocean voyages, and domestic aviation.
2. High potential for efficiency improvement: The N-type silicon wafers used in HIT cells have a higher minority carrier lifetime, and the corresponding structure with amorphous silicon passivation treatment can also achieve a lower surface recombination rate. As a result, the open-circuit voltage of silicon heterojunction solar cells is much higher than that of traditional monocrystalline silicon solar cells, and its efficiency potential is up to 2% greater than that of current PERC cells using P-type silicon wafers.
3. Low cost and simple manufacturing process: HIT batteries combine the advantages of ultra-low temperature manufacturing of thin-film solar cells, avoiding the traditional high-temperature processes. The HIT process is relatively simple, requiring only four steps to complete the entire production process.
4. High stability and high efficiency: HIT batteries have good light stability. No Staebler-Wronski effect was found in the amorphous silicon thin film in the heterojunction, which means that the battery conversion efficiency will not show any signs of degradation due to light exposure.
5. Double-sided battery: HIT battery is an excellent double-sided battery with virtually no color difference between the front and back sides. Moreover, the bifaciality (the ratio of the efficiency of the back side to the efficiency of the front side) can reach over 90%, and can even reach 98% in some cases. The core competitive advantage of generating electricity from the back side is obvious.
HIT batteries are highly likely to become the mainstream technology for next-generation photovoltaic cells, and mass production is very likely to begin this year. Cobalt, a raw material for these batteries, is also likely to be shipped in large quantities as battery production capacity increases. Due to the tightening of cobalt production capacity, cobalt stock prices are likely to rise sharply along with the lithium battery industry.
