Optimizing Laser Scribes: Preventing Module Failure

PHOTOVOLTAIC SCALE UP, PROCESS INNOVATION

Optimizing Laser Scribes: Preventing Module Failure

This is part 1 in our series showcasing the innovative laser and inkjet solutions offered by msolv® for the photovoltaics (PV) industry. We begin with a serious industry issue faced by perovskite module manufacturers using laser technology.

Scribe Optimization – Maximizing Efficiency

Perovskite photovoltaics have emerged as a promising technology in the renewable energy sector, offering high efficiency and low production costs. However, one of many challenges faced by companies tackling the manufacturing process is the method to form each cell-cell interconnect. Laser scribing is the standard, subtractive technique used in module production. However, laser ablation can produce tiny, sharp protrusions along the scribe edge called burrs. These can cause significant issues and ultimately module failure. In this post, we will explore how perovskite interconnect burrs cause module failure and discuss effective methods to remove them.

Interconnect burrs are small, unwanted protrusions that form during the laser scribing process. These burrs can cause a multitude of problems leading to decreased efficiency and potential module failure. For example:

Electrical Shorts
Incomplete Scribes
Decreased Efficiency via Shunting
Structural Weakness

Burrs create unintended electrical pathways, between the ultrathin layers of the cell, leading to localized shunts or even complete shorts that reduce the overall efficiency of the solar module. They can weaken the perovskite, making it more prone to cracking and other mechanical defects which at their worst are intermittent and almost impossible to detect. Any compromise to the structural integrity of the solar module, makes it more susceptible to environmental stressors like heat and humidity.

To avoid these challenges with perovskite solar modules, it’s crucial to eliminate burrs. A typical chemical-mechanical solution is inconvenient for large-scale production and contact deburring processes are not feasible due to risk of contamination of the sensitive layers. The only solution is prevention within—or by adding—a laser process.

A high-repetition rate, solid state (DPSS) laser capable of picosecond or femtosecond pulses, offered on the MSV700 (or other msolv® products), with optimal passes can chamfer or round the edge of the scribe. Short-pulse lasers with custom-shaping of the light distribution offers excellent process control when paired with effective debris extraction and minimizes the risk of the thin film delaminating. The adhesion within the perovskite film is stronger than the adhesion of the film to the substrate. Thus, when hit by the laser, the thin film will delaminate significantly leaving raised sections which stick upwards—a burred edge. Since short pulse lasers are highly effective for targeted removal they limit damage to the surrounding material. If the junction process needs a clean-up, they’re particularly useful for super thin or sensitive layers like perovskite.

Perovskite interconnect burrs pose a significant challenge in the production of high-efficiency solar modules. However, with the right techniques it’s possible to remove these burrs to safeguard yield and efficient performance of perovskite solar cells. By adopting advanced laser methods manufacturers can overcome this hurdle and continue to push the boundaries of solar technology. For more information about this process, get in touch— the msolv® team works closely with every customer to ensure the right solution for their needs. Next in our series (Part 2), we’ll explore the SBS™ process: a new and innovative laser process developed by msolv® that’s redefining solar manufacturing.