Back-Contact technology reshaping the solar PV landscape: progress and outlook for xBC industrialization

As the solar PV industry has entered a new stage that emphasizes high efficiency, high reliability, and low cost, traditional PERC technology has been largely replaced by TOPCon technology since 2023. While TOPCon has become the mainstream due to its excellent cost-performance ratio, major manufacturers are actively pursuing the next-generation crystalline silicon (c-Si) PV cell technology roadmap. Among the leading candidates, back-contact (xBC) technologies—including TBC (TOPCon back contact), HBC (HJT back contact), and HTBC (HJT TOPCon back contact)—have emerged as the most prominent trend, attracting significant attention for their superior conversion efficiency and aesthetic module design. 

Although current production capacity is still concentrated among leading enterprises and remains in a phase of expansion and cost optimization, xBC is widely regarded as one of the most promising mainstream technologies for industrialization following TOPCon and HJT, particularly as the manufacturing process matures and costs decline significantly.

This article examines the major categories of xBC technology, production capacity plans by key manufacturers, and future development trends, assessing its strategic significance and industrial opportunities in the global PV market.
 

Overview of xBC technologies: highest mass-production efficiency among c-Si technologies, along with aesthetic design favored in high-end applications

Table 1. Comparison among major PV cell technologies

xBC has demonstrated several notable advantages over PERC, TOPCon, and HJT technologies. Most importantly, its unique back-contact structure eliminates front-side gridline shading, increasing the light-receiving area and improving light utilization efficiency, resulting in significantly higher conversion efficiency. In terms of mass production performance, mainstream TBC cells have already surpassed 26% efficiency, clearly outperforming TOPCon and HJT.

Secondly, xBC technology features high structural compatibility, enabling flexible integration with both p-type and n-type substrates, as well as with mainstream cell technologies such as TOPCon and HJT. This versatility has given rise to various high-efficiency back-contact architectures—including TBC, HBC, and HTBC—which further enhance cell efficiency and overall performance.

Thirdly, thanks to the simplified front-side zero-busbar (0BB) design and overall aesthetic appeal, xBC modules are strongly favored by end-users and brand companies that prioritize both appearance and high performance. They are particularly well-suited for high-end distributed applications such as premium residential and commercial & industrial (C&I) rooftop installations. In markets where architectural aesthetics are highly valued, such as Japan and most European countries, the appeal of xBC is especially pronounced.
 

Development status: LONGi and Aiko leading the advancement of xBC technology, with production capacity expected to exceed 80 GW in 2025

Figure 1. xBC capacity plans (The information here is subject to the official information published by the companies.)

Regarding the current and future production capacity plans for xBC technology, LONGi and Aiko remain the leading players. As part of LONGi’s hybrid-passivated back contact (HPBC) capacity is being upgraded to TBC technology, along with the commissioning of several new TBC production bases, its TBC cell capacity is expected to reach around 50 GW by 2025. Aiko’s TBC cell capacity reached around 20 GW last year and is expected to increase to 25 GW this year. In addition, the 6 GW project jointly developed by LONGi and Yingfa is scheduled to commence production in the second half of this year. Overall, total xBC production capacity is projected to exceed 80 GW by the end of 2025.

Although there is still a limited number of manufacturers currently adopting xBC technology in mass production, the market has fully recognized the high efficiency and strong performance of xBC cells and modules. Leading companies have already established pilot or R&D lines and, in many cases, publicly announced capacity expansion plans for xBC.

While xBC only began to emerge in 2023, with module shipments that year reaching approximately 7 GW, shipments grew to around 23 GW in 2024 and are projected to rise further to 35–40 GW in 2025, demonstrating a rapid growth trajectory.

Given the current industry-wide overcapacity and the relatively high investment cost of xBC, along with the strong compatibility between TOPCon and xBC technologies, upgrading existing TOPCon capacity to xBC is expected to become a major driver of future xBC capacity growth.
 

Significant cost reduction for xBC: competitively priced against common TOPCon technology

In the PV industry, xBC technology has generally been known for its advantages in high efficiency and aesthetics, but its high cost has hindered wider adoption. InfoLink has been closely tracking technological development trends. As of 2Q25, on the cell side, TBC technology has achieved a notable reduction in silver paste consumption through the adoption of steel mesh screen printing, bringing silver usage down to levels comparable to the mainstream TOPCon technology. In addition, enhancements in screen durability have further reduced metallization costs, now on par with TOPCon.

On the module side, the use of flat ribbons in TBC technology has enabled the mass production of copper-aluminum composite ribbons. While there is still a slight compromise in the module power output, with 1134×2382 mm modules experiencing a reduction of 2–3 W, the lighter weight and lower cost of copper-aluminum composite ribbons have significantly reduced the cost of PV ribbons in xBC modules. This translates to a BOM (Bill of Materials) cost saving of RMB 0.02–0.03/W.

In contrast, due to the complexity of the metallization pattern in TOPCon super multi-busbar (SMBB) technology, steel mesh screen printing remains difficult to mass produce in the near term. In addition, as TOPCon SMBB modules primarily use φ0.24–0.26 mm round ribbons, the combination of their thin diameter and the compression applied during the stringing process increases the risk of exposing the aluminum layer in copper-aluminum composite ribbons, potentially leading to reliability issues.

As a result, the limited feasibility of adopting steel mesh printing and copper-aluminum composite ribbons in TOPCon SMBB technology in the short term has significantly narrowed the cost gap between TBC and common TOPCon.

Figure 2. Glass-glass module cost assessment and comparison, Unit: RMB cents/W

As shown in Figure 2, the cost comparison clearly indicates that common TBC cells, due to the absence of steel mesh printing, still have relatively high silver paste consumption. On the module side, the continued use of common copper ribbons results in higher module costs compared to TOPCon. With higher costs across both the cell and module segments, the technical cost of common TBC remains around RMB 0.07/W higher than that of common TOPCon-SMBB technology.

However, given that xBC technology still holds a clear lead over TOPCon in terms of both cell and module efficiency, xBC manufacturers have introduced copper-aluminum composite ribbons at the module level. While this slightly compromises power output, the efficiency advantage remains significant. More importantly, it enables notable cost reductions on the module side. Coupled with the adoption of steel mesh printing in cell manufacturing, the pre-tax cost (cell + module) for this lower-cost TBC is merely about RMB 0.03/W higher than common TOPCon-SMBB. Given that TBC modules typically command a price premium of around RMB 0.05–0.07/W over TOPCon, the lower-cost TBC has shown stronger cost performance compared to common TOPCon.
 

Outlook: Sluggish PV market constrains rapid xBC growth

Figure 3. Estimated market share by technology, Unit: %

Previously, the technical complexity, high capital investment, and particularly elevated production costs of xBC technology resulted in slow capacity expansion. Although xBC has recently achieved significant cost reductions, demonstrating cost performance on par with or even superior to TOPCon, the PV industry has been reeling from the transition from PERC to TOPCon and is now facing widespread overcapacity, with most technologies currently operating at a loss. Moreover, whether through new installations or upgrades of existing TOPCon lines, xBC deployment requires substantial capital investment. While an increasing number of companies have announced plans to develop xBC capacity, many are still taking a wait-and-see approach, suggesting that the primary obstacle to rapid xBC growth has shifted from high costs to the current PV market downturn. If the market recovers by 2027, xBC’s market share could exceed current projections. Nonetheless, even under the continued market slump, xBC's favorable cost-effectiveness and high-power output make its market share likely to reach about 20% by 2028.