In the race to enhance solar performance, even a 0.1% gain in efficiency represents countless hours of innovation and engineering. DAS Solar has once again pushed the boundaries of PV technology: according to the latest report from CPVT, its self-developed DBC (back-contact) cell has achieved a certified conversion efficiency of 27.77%, with an open-circuit voltage reaching 745.7mV, setting a new internal benchmark for the company. This milestone reflects ongoing breakthroughs in cell architecture and process innovation, delivering a high-performance, reliable, and cost-competitive solution for the next generation of PV.
What is DBC?
In today's PV landscape, TOPCon and Back-contact (BC) technologies are two of the most promising paths forward. TOPCon cells use ultra-thin SiOx/Poly-Si passivated contact layers on the rear side to significantly reduce recombination losses and boost both voltage and efficiency, widely recognized for their maturity and scalability. BC cells, meanwhile, eliminate front-side metallization entirely, increasing the active light-receiving area and offering both visual simplicity and higher power output.
DAS Solar identified the complementary strengths of both technologies and pioneered the DBC architecture, a novel approach that integrates TOPCon's proven passivated contact with the clean look and electrical benefits of BC design. By combining these two leading technologies, DBC creates a new technical pathway. Since its initial launch, the platform has evolved through three major iterations—now culminating in the advanced DBC 3.0 Plus—highlighting DAS Solar's commitment to continuous innovation and independent R&D.
TOPCon×BC: A Powerful Combination Reinforced by N-type Technology
The DBC 3.0 Plus cell is built on DAS Solar's fifth-generation TOPCon platform, applying SiOx/Poly-Si passivated contacts to both the n-type and p-type regions. This enables a rare balance between high passivation quality and low-cost manufacturing, supported by new structures, mechanisms, materials, and processing innovations. The company currently holds over 60 patents related to TOPCon and BC technologies, has led the drafting of more than 10 standards, and participates in several national and provincial research programs, all of which have laid the groundwork for achieving 27.77% efficiency.
Five Key Innovations Driving DBC's High Efficiency
DAS Solar's R&D team has achieved several technical breakthroughs to realize the deep integration of TOPCon and BC architectures.
First, precision laser patterning using ultra-short UV picosecond lasers enables micron- and nanoscale p/n junction structuring, creating finer grid lines that reduce energy loss and enhance photoelectric conversion. Second, an embedded diode system provides real-time hot-spot mitigation by rerouting current from overheated zones, enhancing long-term reliability. Third, a full-area hybrid passivation approach using composite films ensures optimal surface passivation for both p- and n-type regions, reducing recombination losses. Fourth, 0BB (zero busbar) interconnection design minimizes silver paste consumption while maintaining strong electrical performance and reducing material costs. Finally, a black silicon surface structure enhances light-trapping and absorption while improving UV-induced degradation (UVID) resistance, contributing to both efficiency and durability.
Together, these five innovations not only demonstrate DBC's high laboratory efficiency but also ensure scalability and production readiness.
Beyond Cells: Module-level Optimization for Maximum Output
To unleash the full potential of its high-efficiency cells, DAS Solar has also optimized DBC module design. Using an invisible interconnection layout and non-destructive current collection, front-side shading is eliminated and current loss minimized, pushing module efficiency beyond 24.8%. Thermal stress during welding is mitigated through even heat field control, which strengthens long-term mechanical reliability. The module design further enhances hot-spot resistance and delivers outstanding low-light response with a coefficient exceeding 95%, ensuring high yield even during early mornings, evenings, or cloudy days.
In the PV industry, the competition is ultimately defined by the trade-offs between efficiency, reliability, cost, and scalability. DAS Solar's DBC technology disrupts this paradigm by offering all four: high conversion efficiency, modern aesthetics, flexible compatibility, and low-cost potential through advanced metallization strategies and reduced silver use.
The 27.77% cell efficiency is not just a number, it's a signal of what's next. Positioned at the intersection of TOPCon maturity and BC innovation, DAS Solar's DBC 3.0 Plus delivers both laboratory-grade performance and commercial viability. As mass production ramps up, it promises to drive PV toward a future that is not only more efficient, but also more reliable and accessible for all.