by TongweiCN
Prove heterojunction cells can beat TOPCon on power and, with copper instead of silver, on cost, and serve as the base for future perovskite tandem cells.
Silver-free THC module hit 802.43 W and 25.83% (June 2026), its 12th power record.
Updated 3 Jun 2026Checked 11 Oct0 updates this week
Nanometre layers of amorphous silicon coat both sides of the wafer, sealing its surfaces so very few charges are lost before they are collected.
The films go on below about 250 °C, which suits thin wafers and needs fewer steps than TOPCon, but requires costly vacuum deposition machines.
Copper lines replace silver paste on the cells, and busbar-free wires link them, cutting a big material cost and shading less of the cell.
Its well-sealed surfaces make HJT a good base for a perovskite top layer; Tongwei's full-size tandem cells exceed 32.68% in the lab.
| Spec | THC heterojunction modules |
|---|---|
| Record module power | 802.43 WR (reported) |
| Record full-area efficiency | 25.83%R (reported) |
| Module size | 2,384 × 1,303 mmR (reported) |
| Cells per record module | 198 third-cut G12 cellsR (reported) |
| Mass-production power (Oct 2024) | 745 WR (reported) |
| Perovskite-HJT tandem (full-size cell) | Over 32.68%R (reported) |
R reported by the company
Tongwei
Polysilicon, TOPCon and HJT solar cells
Chinese group that is the world's largest maker of solar-grade polysilicon and has shipped the most solar cells of any company for nine years running. It also makes modules and is a major fish-feed producer. Based in Chengdu.
