New Generation Solar Technology
Heterojunction technology (HJT) is a new type of bifacial solar cell that uses a combination of crystalline silicon and amorphous silicon thin-film layers to achieve record-high efficiencies and performance.
HJT panels can absorb sunlight from both the front and back sides, which can increase power output by up to 20%. They also have a low temperature coefficient, which means that they perform well in hot climates. Additionally, HJT panels are expected to have a lifespan of over 30 years, which is longer than most other types of solar cells.
HJT technology is still relatively new, but it is rapidly gaining market share due to its many advantages. As the technology continues to develop and costs come down, HJT panels are expected to become a major player in the solar industry.
What Are the Advantages?
High Conversion Efficiency
HJT solar cells use amorphous silicon (a-Si) thin films as passivation layers to reduce carrier recombination, which can increase the open circuit voltage to 750 mV and boost the efficiency to 24% already in the beginning.
Low Temperature Coefficient
HJT solar cells are made from n-type wafers, which do not have boron-oxygen (B-O) bonds, resulting in no light-induced degradation (LID). Additionally, the transparent conductive oxide (TCO) film on HJT solar cells is conductive, which prevents charge polarization on the surface and avoids potential-induced degradation (PID)
Better Weak Light Performance
N-type solar cells have a longer minority carrier lifetime than bifacial PERC solar cells, which results in better power generation under weak light. N-type solar cells can generate about 0.5% to 1% more power per watt than bifacial PERC solar cells under weak light conditions.
HJT solar modules have a high bifaciality of up to 97%, due to their natural bifacial symmetrical structure. This means that they can generate electricity from both the front and back sides, resulting in energy yield gains of up to 30% in some cases.
The unique design and construction of HJT solar modules make them more durable and long-lasting than other types of solar modules. As a result, HJT solar modules are expected to have a lifespan of over 30 years.
Ultra Low Carbon Footprint
HJT solar cells have a lower carbon footprint (less than 400g CO2/W) than other types of solar cells, such as PERC (more than 700g CO2/W), due to a number of factors, including fewer processing steps, less energy requirements, thinner wafers, and higher efficiency.
The Future of HJT
HJT technology was developed back in the 1980s and gradually developed from a cell efficiency of 14.4% to 26.3%, therefore was regarded as the most revolutionized solar technology today. But a bigger potential is to develop tandem solar cell by cominbing HJT with Perovskite, which can reach an efficiency of more than 30%. As Perovskite is abundantly available, it will bring the cost down dramatically therefore making solar panels more affordable and making it easier to reach net zero.