Heterojunction (HJT) solar cells are gaining global attention for their high efficiency and long-term reliability. With Indian manufacturers now entering the space, HJT is emerging as a next-generation solar technology. However, one of the biggest challenges holding back its widespread adoption is cost, primarily driven by high silver consumption.
Unlike mainstream PERC cells, which require silver only on the front side, HJT cells need silver on both front and rear surfaces for metallization. This leads to silver usage as high as ~22 mg/W, making HJT one of the most silver-intensive cell architectures. As silver prices remain volatile and global PV demand continues to rise, silver cost and availability have become critical bottlenecks.
Electroplating: A Game Changer for Cost Reduction
Electroplating has emerged as a compelling solution, allowing manufacturers to replace expensive silver with cost-effective metals like copper or aluminum — without sacrificing electrical performance. Copper, in particular, is ~99% cheaper than silver and offers comparable conductivity when properly deposited.
Beyond cost savings, electroplating enables:
- Finer line widths (as low as 20 µm), reducing shading losses
- Improved light absorption and cell efficiency
- Scalable processes, now compatible with automated inline manufacturing
- Lower material waste through selective deposition techniques
These benefits make electroplating a commercially viable upgrade for manufacturers seeking to maintain HJT’s performance edge while achieving cost competitiveness.
Electroplating vs. Screen Printing: A Side-by-Side Comparison
| Aspect | Screen Printing | Electroplating |
| Material Efficiency | Thick silver paste; high wastage | Ultra-low silver; copper/aluminum-based alternatives |
| Line Width & Shading | 60–80 µm; higher shading losses | 18–25 µm; better light capture and aesthetics |
| Conductivity | Dependent on silver’s properties | Comparable with plated copper (with barrier layers) |
| Reliability | Proven long-term reliability | Enhanced with Ni barrier layers; proven in recent field data |
| Equipment Compatibility | Standard in PERC & TOPCon lines | Compatible with HJT after moderate retrofitting |
| Cost | High due to silver dependency | Up to 60–70% lower metallization cost |
| Scalability | Mature but peaking | Rapidly maturing; inline systems now commercially available |
Advanced Plating Techniques for HJT
Electroplating for HJT is no longer confined to the lab. Several techniques are already being used in commercial production, while others are at advanced R&D or pilot stages with promising potential.
- Plated Copper with Barrier Layers
- Uses nickel or silver seed layers to prevent copper diffusion
- Cuts silver use by up to 80%
- Adopted by solar manufacturers like Akcome Technology.
- Light-Induced Plating (LIP)
- Uses light-generated charge carriers to drive metal deposition
- Compatible with high-speed inline manufacturing
- Laser Transfer and Plating (LTP)
- Combines precise laser patterning with copper electroplating
- Reduces metal waste and enables fine-line designs
- Used selectively in precision-focused commercial lines
- Mask-and-Plate Technologies
- Applies photoresist or masks to define metal regions before plating
- Enhances accuracy and reduces material usage
- Adapted from semiconductor fabrication and commercially applied in some facilities
- Additive Manufacturing-Based Plating
- Uses inkjet or aerosol-based deposition to apply copper
- Potential path toward silver-free HJT cells
- Still in R&D/pilot stage, not yet adopted at scale
Final Word
The future of HJT solar cells hinges not only on design innovation but also on mastering next-gen metallization. Electroplating, once seen as a complex process, is now commercially viable, scalable, and essential for reducing costs without compromising performance.
For Indian manufacturers, embracing electroplating is more than a cost-cutting move—it’s a strategic imperative. With smart investments in advanced tooling, R&D partnerships, and process optimization, India can cut its silver dependency, boost margins, and sharpen its global edge.
To lead in high-efficiency solar manufacturing, India must move beyond tradition.
Electroplating is no longer optional—it’s the way forward
