LONGi presented its BC technology platform and module developments at the TaiyangNews Next-Gen PV Technologies Conference 2026
The company’s Full-Screen and Advanced Contact Matrix technologies focus on increasing active area
Its Integrated Conductive Backsheet combines encapsulation, insulation and current-collection functions, and can increase module power by 3 W to 5 W, according to LONGi
Vertically integrated solar manufacturer LONGi presented its latest technology developments at the TaiyangNews Next-Gen PV Technologies Conference 2026. Barry Chen, Senior Product Solution Manager at LONGi, discussed the company’s cell technology roadmap and BC manufacturing plans. He also outlined 3 BC-related innovations: Full-Screen Technology, Advanced Contact Matrix (ACM) and an Integrated Backsheet.
LONGi is working on multiple cell technologies, including heterojunction (HJT), back contact (BC), TOPCon, and perovskite-silicon tandems. According to Chen, LONGi achieved a certified cell efficiency of 28.13% with its HIBC. The company also achieved a world-record efficiency of 35.5% for a crystalline silicon-perovskite tandem cell.
Among these technologies, LONGi has positioned HPBC 2.0 as its main commercial cell platform. Chen compared BC with TOPCon, the 2 technologies currently dominating commercial development. According to him, LONGi’s mass-produced BC modules deliver around 654 W, compared with approximately 624 W for standard TOPCon 1.0 modules.
TOPCon products are advancing through multi-cut cell formats and improved cell-processing techniques. Chen noted that these developments can also be applied to BC products. LONGi therefore expects BC modules to maintain a power advantage of approximately 20-30 W over TOPCon.
Full-Screen Technology
Full-Screen Technology combines gapless cell spacing with a Hidden Busbar design to increase the module’s active area. According to LONGi, the design uses more of the module surface for power generation while improving reliability and creating a cleaner front-side appearance.
In conventional modules, interconnection ribbons require gaps between adjacent cells. LONGi instead uses a slightly overlapping cell layout with a straight-line interconnection structure. According to the company, this distributes stress more evenly at the cell overlaps and reduces the risk of microcracks.
The Hidden Busbar design is enabled by moving all electrical contacts to the rear of the BC cells. This eliminates front-side busbars and the additional spacing associated with them. LONGi incorporated Full-Screen Technology into the Hi-MO 9 Prime showcased at Intersolar Europe 2026.
The Hi-MO 9 Prime delivers up to 680 W of power and reaches a maximum efficiency of 25.2%. It uses 132 half-cells in a 2 mm dual-glass configuration and has a bifaciality of 75±5%. Its electrical architecture limits the effect of localized shading, allowing unshaded sections to continue generating power.
Advanced Contact Matrix
Advanced Contact Matrix (ACM) is intended to address rising silver costs and the reliability challenges associated with increasingly narrow metallization fingers. Reducing finger width lowers silver consumption, but narrow fingers are more susceptible to breakage and can create contact problems during interconnection.
LONGi’s ACM technology uses a conductive contact that is 5 to 7 times wider than a conventional silver finger. Its two-layer alloy structure combines a narrow cell-contact layer with a wider, highly conductive current-carrying layer. The first layer establishes electrical contact with the cell, while the second transports the collected current.
According to LONGi, the wider conductive path reduces electrical resistance and improves reliability. ACM has entered mass production, with Chen indicating that the company has approximately 21 GW of manufacturing capacity for the technology.
Integrated Backsheet
LONGi also presented a 3-in-1 Integrated Conductive Backsheet that combines the backsheet, encapsulation film, and conductive foil in one structure. It is designed to improve moisture protection, current collection, and mechanical support.
Chen said conventional encapsulation films have a water-vapor transmission rate (WVTR) of approximately 50 g/m²/day, compared with around 1 g/m²/day for a CPC backsheet. The conductive foil incorporated into LONGi’s Integrated Backsheet has a substantially lower WVTR, strengthening the module’s protection against moisture ingress.
The conductive foil also replaces the ribbons conventionally used for current collection. These ribbons are approximately 250 µm thick, compared with around 130 µm for mainstream TOPCon cells and approximately 140 µm for LONGi’s BC cells. According to Chen, LONGi retains the slightly higher cell thickness to improve mechanical strength and resistance to microcracking.
Because conventional ribbons are thicker than the cells, they can create localized stress at the contact points. The number of such stress points can increase as manufacturers add more ribbons to each cell. The company’s conductive foil covers almost the entire rear surface of the cell, providing broader mechanical support.
The foil is around 40 µm thick, but LONGi says it increases the overall conductive cross-sectional area by approximately 85%. According to the company, replacing ribbons with conductive foil can increase module power by around 3 W to 5 W while reducing mechanical stress and improving long-term reliability.
LONGi combines the Integrated Conductive Backsheet with Full-Screen Technology in its Hi-MO X10 product, which reaches a maximum power output of 690 W.
