JinkoSolar Reports 28% Peak Efficiency for Back-Contact TAC Cell

• JinkoSolar said its new TAC back-contact solar cell reached a peak efficiency of 28%, a company-reported figure with no certifying lab named.
• That is 0.29 percentage point below the 28.29% silicon cell record LONGi reported in September, verified by Germany's ISFH.
• The first TAC product is a 510-W, 25.52%-efficient module for homes; JinkoSolar has not disclosed a price or production capacity.

Jinko Solar Co. unveiled a back-contact TAC solar cell with a peak efficiency of 28% at its Global Tech Day in Shanghai on Oct. 17. The figure is company-reported. JinkoSolar did not name a testing lab or give the cell area.

TAC, short for TOPCon-based Amorphous-Si Passivating Cell, puts both electrodes on the rear and leaves the front free of metal. Electrons exit through a TOPCon contact: ultrathin silicon dioxide under heavily doped polysilicon. Holes pass through amorphous silicon layers borrowed from heterojunction cells, which the company says lift open-circuit voltage. Laser patterning and dielectric films keep the regions apart.

The 28% is a peak for the best cell, not a production average or a module rating. It falls just short of the single-junction silicon record. In September, LONGi Green Energy Technology Co. reported 28.29% for a hybrid interdigitated back-contact cell, verified by Germany's Institute for Solar Energy Research Hamelin (ISFH).

The cell in numbers

• 28% peak cell efficiency for TAC, company-reported, with no certifying lab or cell area disclosed.
• 0.29 percentage point below LONGi's ISFH-verified 28.29% record (list.solar calculation).
• 0.21 percentage point above the 27.79% TOPCon cell JinkoSolar had certified by ISFH in November 2025 (list.solar calculation).
• 95% of the 29.4% theoretical limit for single-junction crystalline silicon cells (list.solar calculation).
• 510 W and 25.52% efficiency for the first TAC product, an all-black 48-cell Tiger Neo 5.0 module.
• 0.72 percentage point above the 24.8% module efficiency of JinkoSolar's mainstream Tiger Neo 3.0 TOPCon panel (list.solar calculation).
• 30 W more than conventional back-contact modules, or 6.3% over an implied 480-W baseline (list.solar calculation).

JinkoSolar is aiming the Tiger Neo 5.0 at villas and other high-end homes. Its temperature coefficient is -0.24% per degree Celsius, against -0.26% for Tiger Neo 3.0. Utility-scale and commercial projects will stay on Tiger Neo 3.0, which logged 30 GW of orders in its first 10 months, the company said.

TAC "is not simply a back-contact structure," JinkoSolar said in a statement, calling it "a genuine advance in cell technology."

JinkoSolar estimates the module's price premium pays back in about 8.6 years on villa roofs in the Netherlands and Germany, and 4.4 years in Sydney. It has not disclosed a price or TAC production capacity. Perovskite tandems and space-based PV will be built on the same TOPCon platform, the company said.