HJT

HJT stands for Heterojunction Technology, a solar cell design that sandwiches a crystalline silicon wafer between thin layers of amorphous silicon. This creates a heterojunction — a junction between two different semiconductor materials — on both the front and rear of the cell.

The amorphous silicon layers provide excellent surface passivation, dramatically reducing electron recombination and pushing cell efficiencies above 25% in commercial production. The HJT cell holds the current world record for silicon-based cell efficiency.

One of HJT's standout features is its exceptionally low temperature coefficient, typically around -0.25% per degree Celsius versus -0.35% to -0.40% for conventional PERC cells. This means HJT panels lose less output in hot weather, making them particularly advantageous in warm climates where panel temperatures routinely exceed 50°C.

The manufacturing process for HJT is simpler than TOPCon in terms of the number of process steps, but it requires entirely new production equipment operating at lower temperatures. This capital investment has slowed adoption compared to TOPCon, which can retrofit existing PERC lines.

HJT panels are inherently bifacial and pair well with half-cut cell designs. As equipment costs decline and production scales up, HJT is positioned to become increasingly competitive alongside TOPCon as the industry's next-generation technology.