TCL Solar is developing its BC platform using TCL Zhonghuan’s established expertise in 210 mm silicon wafers
Its BC technology combines high-lifetime wafers, submicron texturing, directly processed half-cut wafers, 0BB interconnection, and lithography-based patterning
The company’s portfolio includes modules for utility and residential applications
BC technology places both positive and negative metal contacts on the rear of the solar cell, eliminating front-side metallization shading and increasing the light-receiving area. However, realizing its efficiency potential requires high-quality wafers, optimized surface texturing, and cell interconnection designed for the rear-contact architecture.
At the TaiyangNews Global PV System Technology Trends Conference, Xiao Geng, Deputy Chief Engineer of Product Planning at TCL Solar, outlined the company’s developments across BC wafers, cells and modules.
TCL Solar’s BC development builds on TCL Zhonghuan’s wafer expertise, with cumulative shipments of 210 mm wafers exceeding 300 GW. According to Geng, wafers developed specifically for BC cells achieve minority-carrier lifetimes of around 10,000 µs and tightly controlled oxygen content. He attributed these characteristics to improved raw-material purification, control of metallic impurities, and the transfer of oxygen-control capabilities from semiconductor manufacturing.
At the cell level, TCL Solar uses submicron surface texturing with a roughness of less than 1 µm. The company says this limits short-wavelength reflectance to below 2% and total reflectance to below 9.5%.
Its Pattern OPT process uses lithography-based patterning instead of laser processing. According to Geng, this avoids thermal damage, improves pattern uniformity, and increases manufacturing yield and module reliability. He added that the process lowers production costs compared with the company’s previous approach. TCL Solar also claims its electrode-pattern optimization raises the low-light performance coefficient to above 95% under comparable test conditions.
The company calls its latest TOPCon-derived BC platform C2. Its technology roadmap combines low-cost finger metallization, optimized polysilicon passivation, 0BB interconnection, and high-density packaging. The company is targeting mass-production cell efficiency above 27%, module bifaciality of around 80%, and module efficiency exceeding 25%. It expects these developments to bring BC module manufacturing costs closer to those of TOPCon products.
At the module level, TCL Solar combines directly processed half-cut wafers with 0BB interconnection and high-density point-contact welding. According to the company, directly processing half-cut wafers avoids the edge-recombination losses caused by cutting completed cells. The interconnection design increases the number of current-transmission paths and contact points, contributing a module-level power gain of around 5 W.
For residential modules, the C2 platform combines hidden busbars with overlapping cells in a full-screen design, eliminating visible gaps between the cells. The company claims this design increases module power by between 5 W and 10 W.
TCL Solar also employs a cell-level hotspot-mitigation design, which it claims can reduce hotspot temperatures by approximately 50°C compared with conventional TOPCon modules. Its quasi-bypass-diode design is said to improve energy generation by more than 10% under complex partial-shading conditions. These gains depend on the testing and operating conditions.
For utility-scale applications, TCL Solar presented the bifacial G12R-66P module, which reaches 680 W and 25.2% efficiency. For residential and distributed-generation applications, it presented the 197-54P monofacial dual-glass module, delivering up to 505 W and 24.7% efficiency.
The company recommends choosing between BC and TOPCon based on the project environment. For desert power plants, where bifacial gain is a priority and land costs are relatively low, it considers its T5 Pro multi-cut TOPCon series more suitable. For applications with high structural, foundation, or land-related costs, the company expects the higher front-side power density of BC modules to provide greater system-level value.
Geng cited offshore PV as an example. TCL Solar modeled a 100 MW project comparing a 645 W T5 Pro module with a 655 W BC module of the same dimensions. It calculated a total balance-of-system cost of RMB 3.2158/W for the TOPCon system and RMB 3.1703/W for the BC system, representing a reduction of RMB 0.0455/W.
According to the simulation, the BC module’s partial-shading performance compensated for its lower bifaciality, resulting in comparable modeled energy yield. The calculated annual yield was 1,271 kWh/kW for the BC system and 1,269 kWh/kW for the TOPCon system. Under the stated project assumptions, TCL Solar calculated that the BC system reduced the levelized cost of electricity by around 1%.
