Why TOPCon?
TOPCon Technology, or Tunnel Oxide Passivated Contact, was firstly presented in the industry in 2013 by a group of German researchers. It is a type of solar panel technology that aims to improve the efficiency of solar cells. This article will explain about the TOPCon solar panel technology and its advantages in detail. Let’s get started!
What Is TOPCon Solar Panel Technology?
TOPCON stands for Tunnel Oxide Passivated Contact. TOPCON solar cell is a form of solar cell that functions as a tunnel oxide layer to passivate the contact between the front and rear layers of the cell. This passivation layer reduces the recombination of charge carriers, improving the cell’s efficiency. In other words, TOPCon solar cells are also known for their excellent spectral response and low-temperature coefficient, making them perfect for use in hot and wet climates.
Indeed, the TOPCon solar cell structure corresponds to a thin tunnel oxide layer sandwiched among a transparent conductive oxide (TCO) layer and a p-doped crystalline silicon layer. The TCO layer acts as a front link for the solar cell, while the p-doped layer acts as the absorbance layer. The tunnel oxide layer acts as a passivation layer and prevents the combination of charge carriers at the solar cell’s surface. Increased efficiency modifies the solar panel to capture more energy per unit area.
TOPCon technology belongs to the N-type cells. The silicon wafer is treated with chemicals for better electricity presentation; N-type and P-type differ from the material used to dope it. P-type cells are doped with boron, while N-type cells are doped with phosphorus. The performance of phosphorus against boron is that boron can be susceptible to degradation because of oxygen, which is not the case for phosphorus. In addition, phosphorus doping adds free electrons to the wafer, which increases the ratio.
N-type cells are branched into PERT, Topcon, HJT, and IBC. TOPCon cells are the main symbol. They were first presented in 2013 but have been native by manufacturers only since 2019.
N-Type TOPCon Silicon Cells
Cells built on an N-type silicon substance offer better performance over the more average P-type silicon due to a greater endurance to impurities, which increases the overall ratio. In addition, N-type cells have a lower temperature coefficient than mono and multi-P-type cells. N-type cells also have a much lower rate of LID or light-induced degradation and do not mostly suffer from LeTID (light and elevated temperature-induced degradation), a communal problem with P-type cells.
TOPCon or Tunnel Oxide Passivated Contact advertises a specialized rear-side cell passivation technique that aids in decreasing the internal recombination losses in the cell and boosts cell efficiency. The procedure has been accessible for years but is now the new industry standards as manufacturers strive to increase ratio and demonstration.
Working of TOPCon Solar Cells
TOPCon solar cells combine layers and materials to capture and convert sunlight into electricity. The front layer of the cell is usually made of a highly-doped silicon material, while the back layer is made of a low-doped silicon material. The tunnel oxide layer is placed between the front and back layers to passivate the contact.
When sunlight hits the cell, it creates electron-hole pairs in the front layer. These charge carriers are then separated by an electric field and collected by metal contacts on the front and back of the cell. The passivation layer reduces the recombination of the charge carriers, improving the cell’s efficiency.
Structure of TOPCon Solar Cell
TOPCon solar cells have numerous advantages over traditional solar cells. Firstly, they are highly efficient, meaning they can create more electricity from the same quantity of sunlight. This makes them perfect for large-scale solar power plants, where maximizing efficiency is crucial.
Secondly, TOPCon solar cells have a lower temperature coefficient than traditional solar cells. This means their efficiency does not decrease as much in hot and humid climates. This makes them ideal for use in regions with high ambient temperatures, such as the Middle East and Africa.
Finally, TOPCon solar cells have an excellent spectral response. This means that they can create electricity from a broad range of the solar spectrum and consider the blue and green parts of the spectrum. This makes them ideal for use in areas with high diffuse light levels, such as cloudy or overcast regions.
Advantages of TOPCon Solar Cell Technology
There are numerous advantages of TOPCon solar cell technology, such as:
· Manufacturing Process
TOPCon modules can be manufactured with the corresponding machines as P-type modules; adopting TOPCon cells doesn’t necessitate high capital investment for manufacturers.
· Higher Efficiency
TOPCon cells modify more sunlight than P-type cells, which results in a higher cell and module ratio. TOPCon cells can reach 28% efficiency (the PERC cell’s maximum efficiency is approximately 24%).
· Lower Degradation
TOPCon modules have low power degradation during the 1st year and the 30 years of PV panel usage, compared to PERC panels.
· Lower Temperature Coefficient
The temperature coefficient is the proportion of power output misplaced by a solar panel for all degrees of temperature modification. It impacts the power generation of PV modules in hot situations. TOPCon cells have the best resistance to high temperatures, which means the ratio of TOPCon modules will be higher in hot climates than that of modules of PERC.
· Bifaciality Rate
TOPCon cells have an improved power increase in bifacial modules than PERC modules. It is an essential ingredient as bifacial solar power is becoming increasingly popular.
· Low Light Performance
The modules of TOPCon have high efficiency in low light conditions, extending the electricity generation period during the day and improving the installment’s operation over time.
· Compatibility
TOPCon technology is compatible with existing PERC production lines and can be retrofitted and upgraded at a low cost, which helps to realize large-scale production quickly and reduce costs.
· Cost Reduction Path
With the advancement of material and process technologies, such as wafer thinning, metallization paste improvement, and equipment localization, the cost of TOPCon cells is expected to decrease further.
TOPCon sun oriented cell innovation is a changing item that redesigns the plan of the PERC/Sprightly sun powered chargers.
This innovation has proactively demonstrated worth by arriving at efficiencies approach the Shockley-Queisser limit for single p-n intersection sun oriented cells and convey a superior exhibition overall.
The sun oriented industry is beginning to get to know TOPCon sun powered cell innovation. LONGi previously sent off its bifacial modules in 2021, however most producers will be letting their high-proficiency TOPCon sunlight powered chargers out of the second (Q2) to the last quarter (Q4) of 2023.
It is conceivable that from the get go, TOPCon sunlight based cell innovation will have somewhat more costly expenses than PERC/Sprightly sun powered chargers, however investigators expect that the expense for TOPCon sunlight based chargers will fall lower than the ongoing expense of PERC sun oriented cell innovation.
The way for TOPCon sun based cell innovation is likewise not totally liberated from contest. There are different innovations highlighting an intriguing extraordinary potential to conflict with this recently redesigned innovation, including HJT as it is additionally evolved, and interdigitated back-reached (IBC) sun powered cell innovation.
