HIUV highlighted latest TOPCon module encapsulation solutions, 0BB interconnection technology with overlay solution, as well as encapsulant recommendations for front and rear side for different cell technologies at the TaiyangNews Conference
The company has developed co-extruded EPE film with advanced features like optimized additive formulations that enhance the product’s anti-PID polarization performance, as well as a strengthened POE layer within the EPE structure to effectively prevent lamination bubbles
HIUV introduced an innovative co-extruded EXP film – P507S – as a cost-effective alternative to pure POE film
The company promoted dual-glass dual-EVA configuration, featuring low acetic acid, high anti-PID property, and high moisture barrier, for TOPCon module
HIUV also introduced film for busbarless (0BB) interconnection
The long-term reliability and durability of TOPCon cell technology-based PV modules depend on the optimal combination of front and rear side encapsulants to balance cost and quality. These modules are available in either a glass-glass or glass-backsheet configuration. The former, though largely accepted in the PV market, has been reported to have several potential reliability risks in the field under several environmental stresses. Multiple PV material companies are addressing these challenges through advancements in encapsulant technology.
Jitin Rai Khanna, Global Sales Director at HIUV, a Chinese PV material company, shared some details about the company's latest TOPCon module encapsulation solutions and a 0BB interconnection technology with overlay solution, as well as the company's encapsulant recommendations for the front and rear side for different cell technologies at the TaiyangNews High-Efficiency Solar Technologies 2024 Conference (see HIUV presentation here).
HIUV Materials Technology, the Shanghai-headquartered specialty polymer films manufacturer, is equipped with up to 120 GW annual film production capacity and has 6 global production bases. Having entered the PV encapsulant film-making business in 2009, the company successfully developed an anti-PID EVA in 2012, followed by the making of pre-crosslinked white EVA in 2014. It also successfully developed a co-extruded POE film in 2018.
The company has adopted ongoing advancements in encapsulant technology to develop several improved encapsulant solutions to align with evolving cell technologies.
HIUV’s latest co-extruded EPE Film, the top choice for module encapsulation in TOPCon, incorporates multiple technological innovations. These include optimized additive formulations that enhance the product’s anti-PID polarization performance, as well as a strengthened POE layer within the EPE structure to effectively prevent lamination bubbles. The company also noted that it is possible to achieve up to 100% lamination yield with no additional padding required at the edges during the mixed sealing process between EPE and EVA at the module lamination stage. These claims have been validated by multiple customer internal validation tests.
Recently, HIUV introduced an innovative co-extruded EXP film – P507S – as a cost-effective alternative to pure POE film. This film features a lower gram weight by significantly reducing the amount of POE resin and includes a middle layer of X-structural strengthening sandwiched between the POE and EVA layers.
To align with the preferences of TOPCon module makers for cost-effective, high-efficiency production, the company introduced a dual-glass, dual-EVA configuration, featuring modified EVA films in either transparent or white. This advanced EVA film series - S201MT / S201W - offers multiple advantages, such as a higher moisture barrier, ultra-low acid value, and strong anti-PID properties. The anti-PID functionality of the EVA film works by capturing adsorbed ions and blocking metal ion penetration through cation exchange or complexation, which reduces the impact of impurity ions on solar cell performance. Additionally, the low-acetic acid value of the EVA provides excellent anti-corrosion properties in hot and humid environments. Other performance-enhancing mechanisms in this advanced EVA include the addition of ion trappers, increased cation barrier properties, and reduced chemical and electrochemical corrosion of cells.
In-house testing to validate the latest dual-EVA configuration in dual-glass standard TOPCon modules showed that when the modules were stored in a dark room for 2, 6, and 12 hours, EL imaging revealed improved visibility post sunlight exposure, indicating a self-healing effect. After exposure to sunlight for up to 8 hours, the EL imaging revealed that all cells regained functionality, suggesting recovery from PID degradation. However, when testing the same configuration with LECO process metallized TOPCon cells, recovery from PID degradation was observed after just 4 hours of sunlight exposure. According to the company’s in-house lab test data, LECO cells are more light-sensitive than non-LECO cells, making power recovery easier under light.
The 0BB cell stringing and module packaging technology offers 4 different methods: light or thermal curable adhesive-fixed welding tape, cell face film, welding + adhesive-fixed welding tape, and welding tape film. The first 2 methods, compatible with skin film technology, use either lamination-forming alloy technology or a heating plate with lamination-forming alloy. HIUV’s latest 0BB interconnection skin film features low fluidity, thermal dimensional stability, and high viscosity.
The company recommends the following front and rear side encapsulants for different cell technologies: EVA + white EVA encapsulation for PERC cells; EPE + white EVA for n-TOPCon; EPE + white EVA for HJT cells; EPE + white EVA for p-type BC cells and n-type BC cells.