LONGi has pushed crystalline silicon solar technology to a new milestone, achieving a certified 28.29% conversion efficiency with its HIBC solar cell technology.
LONGi HIBC solar cell moves crystalline silicon closer to its theoretical limit
Crystalline silicon has taken another step toward the Shockley-Queisser limit, the theoretical efficiency ceiling for single-junction solar cells. The latest advance comes from LONGi, whose HIBC solar cell technology, short for Hybrid Interdigitated Back Contact, has set another world record with an independently verified photoelectric conversion efficiency of 28.29%.
It is the latest in a series of records for the company. LONGi’s back-contact solar technology has steadily reached new performance milestones, supported by an extensive research strategy and targeted investment. In 2025 alone, LONGi spent 4.3 billion yuan, or roughly $600 million, on research and development activities.
The goal is clear: to lead the solar industry into a new era of higher efficiency and greater competitiveness, while potentially helping drive the transition from single-junction to tandem solar technologies.
TOPCon vs. BC
For now, the main benchmark remains TOPCon, the technology that currently dominates the industry. In terms of performance, however, back-contact technology has already surpassed TOPCon photovoltaics at both the cell and module levels, including in temperature coefficient and shading performance.
Another advantage is the potential to replace much of the conventional silver paste used for metal contacts with copper-based metallization processes.
Cost, however, remains a major hurdle. TOPCon is a natural evolution of PERC, the industry’s previous mainstream technology, and can largely be manufactured by upgrading existing production lines. HIBC, by contrast, relies on more complex processes and specialized equipment.
That means higher capital costs and, in turn, higher selling prices. Even so, the technology’s potential is significant, and back-contact architectures could challenge TOPCon’s market leadership sooner than expected.
How LONGi’s HIBC solar cell technology works
So how does HIBC photovoltaics work? As its name suggests, Hybrid Interdigitated Back Contact is a hybrid-passivated back-contact technology that combines high- and low-temperature processes.
The architecture integrates features of heterojunction technology, or HJT, with those of conventional back-contact cells. From HJT, it draws on passivation-material physics and thermochemical processes. From BC technology, it adopts an architecture in which all electrical contacts are placed on the rear of the cell in an interdigitated pattern, leaving the front surface completely unobstructed.
According to LONGi, the architecture can reduce efficiency losses by more than 70% compared with conventional cells, improve temperature performance and, most importantly, enable high power output, with modules exceeding 700 W while maintaining relatively compact dimensions.
Using this approach, LONGi has already broken the world record three times this year, raising cell efficiency first to 28.04%, then to 28.13% and now to 28.29%. The latest result was certified by the Institute for Solar Energy Research Hamelin, or ISFH.
“The efficiency of crystalline silicon solar cells is approaching its technical limit, reaching 96.2% of the theoretical limit,” the company said in a statement.
LONGi added that HIBC technology has also been paired with modules delivering more than 700 W, which the company said demonstrates both the technology’s readiness for mass production and its ability to bring advanced photovoltaic technologies to market.
