PERC solar cell technology is currently at the top with the highest market share of 75% in the solar industry, while heterojunction solar cell technology started to be adopted in 2019 and its market share was only 5.2021% by 2019. TOPCon is almost non-existent in the market, already accounting for 8% of the PV market, but it may start to grow in 2023 as major manufacturers switch from PERC/PERT to TOPCon.

Considering the technical specifications, PERC technology has been left behind by heterojunction and TOPCon solar cell technologies. PERC has an efficiency of 24.5% and a bifacial coefficient of 70%, while TOPCon has an efficiency of 26.1% and a bifacial coefficient of 85%, while a heterojunction has an efficiency of 26.56% and a bifacial coefficient of 92%. Compared with TOPCon, the temperature coefficient of PERC solar cells is worse at 0.3%/ºC, while the temperature coefficient of heterojunction solar cells is even lower than 0.21%/ºC.

Heterojunction solar cells may look promising, but the technology has had major setbacks due to the high cost of producing solar cells and their incompatibility with current technology's production lines. This is where TOPCon solar cells have a head start, because TOPCon solar cells require virtually the same production line as PERC/PERT, and the cost is very similar.

Considering that the technical specifications of HJT and TOPCon solar cells are similar, but considering the setbacks of HJT technology, it is understandable why major manufacturers such as Trina Solar, JinkoSolar, LONGi, etc. choose TOPCon solar cells over HJT .