The core components for the manufacturing of solar cells using heterojunction technology (HJT) are HELiAPECVD and PVD. The systems are perfectly coordinated, both technologically and with regard to their total throughput of 2,400 wafers per hour.
HELiA – ‘High Efficiency Low impurity Apparatus’ – is a platform for two coating processes in heterojunction-based cell coating.
The HELiAPECVD with the S-CubeTM applies the intrinsic a-Si layer for passivation, as well as the amorphous and doped a-Si layers, p and n. The HELiAPVD carries out front and rear surface coating using conductive TCO – with no turning of the wafer required.
Thanks to low operating temperatures, heterojunction is the ideal technology for the very thinnest wafers.
Benefits of HELiA Heterojunction cell coating:
- Heterojunction technology combines advantages of amorphous silicon (thin film) with advantages of monocrystalline silicon wafers
- Highest cell efficiencies of more than 24% with further growth potential
- Reduced production process with only 6 steps
- Significant increase in energy yield thanks to a top-class temperature coefficient of -0.25%/K
- Ideal for thin wafers and ready for combination with SmartWire Connection Technology (SWCT)
More details about both HELiA machines.
HELiAPECVD - Maximum passivation
High-quality amorphous silicon (a-Si) layers are a key factor in producing high-efficiency heterojunction solar cells. Both intrinsic a-Si layers for passivation and doped a-Si layers for manufacturing heterojunction cells can be deposited with the HELiAPECVD system type.
The a-Si layers are deposited using the PECVD (plasma-enhanced chemical vapor deposition) process. Meyer Burger developed a special patented plasma reactor - the S-Cube - for this purpose. This ensures that a-Si layers with outstanding electrical and passivation properties are deposited homogeneously.
HELiAPVD - Low-cost TCO coating
Heterojunction cells are bonded on both sides by means of transparent, conductive oxide (TCO) layers, deposited using the PVD (physical vapor deposition) process.
In the HELiAPVD sputtering system, differing contact layers (including multiple layers and metal layers) can be deposited successively on the front and rear of the wafers without the need to turn the wafers between coating processes.
By using cylindrical sputtering magnetrons, a high target utilization rate is achieved, thus ensuring a cost-effective coating process.