HJT is short for “Heterojunction Technology”, it is a kind of N type Mono Bifacial solar module. With the advantages of simple manufacture process, high electric-producing efficiency and low LCOE, HJT is becoming the industry hot spot.
The structure of HJT solar cell.
The structure of heterojunction solar cell is as below. At the center is the N type mono silicon wafer. At first, deposite the intrinsic amorphous silicon thin film (i-a-Si:H) and P-type amorphous silicon thin film (p-a-Si:H) on the front of the c-Si(n). Secondly, deposite the intrinsic amorphous silicon thin film (i-a-Si:H) and N-type amorphous silicon thin film (n-a-Si:H) on the rear side of c-Si(n). At last, deposite the transparent oxide conductive film (TCO) on both sides of the structure and process the metal electrode, then the HJT structure is finished.
The process of HJT solar cell
The manufacture process of the heterojunction solar cell is very simple, can only be divided into several process: texture, a-Si Front/Rear side deposition, TCO Fron/Rear process, Print Front and Back, Curing and Test & Sort. It is much easier than other types of solar cell manufacturing. At the same time, HJT solar cell process requires low process temperature, avoiding the damage made by high temperature process, and reducing the emissions.
The advantage of HJT solar cell.
- No PID Phenomenon.
- Low temperature manufacturing process
- High efficiency
- Thinner thickness.
- Low temperature coefficient value
- Great weak light effect.
- High open-circuit voltage
The weakness of Heterojunction solar cell.
- High manufacturing equipment investment
- Strict manufacturing process
- High cost for the TCO and low temperature silver paste.
- Require low temperature solar module packaging technology.
With the solar cell technology development, more and more enterprises is enlarging their investment in the heterojunction solar tehnology routine. It is predicted the 4-7 GW HJT production capacity will be released in 2020, more than the total capacity in previous years. So the year 2020 will be the First Year of HJT Industry.