HJT heterojunction cells subvert the traditional cell structure, and have the advantages of high conversion efficiency, simple manufacturing process, thin silicon wafer application, low temperature coefficient, no light-induced attenuation and potential attenuation, and double-sided power generation. There is an advantage in conversion efficiency that significantly exceeds PERC. The output efficiency of PERC is 10% lower than that of heterojunction, which means that for battery components with the same power index, in the entire power generation cycle, heterojunction will generate 10% more electricity than PERC.

Features and advantages of heterojunction cells (HJT cells)

1. No PID phenomenon: Since the upper surface of the battery is TCO, the charge will not generate polarization on the TCO on the battery surface, and there is no PID phenomenon. At the same time, the measured data also confirmed this point. Technology application and prospect of heterojunction solar cells

2. Low-temperature manufacturing process: The processing temperature of all HJT battery processes is lower than 250, which avoids the process of high-temperature diffusion and junction with low production efficiency and high cost, and the low-temperature process makes the optical bandgap, deposition rate, and The absorption coefficient and hydrogen content are controlled more precisely, and adverse effects such as thermal stress caused by high temperature can also be avoided.

3. High efficiency: HJT battery has been refreshing the world record of mass-produced battery conversion efficiency. The efficiency of HJT cells is 1-2% higher than that of P-type monocrystalline silicon cells, and the difference between them is slowly increasing.

4. Technical application and prospect of high light stability heterojunction solar cells: the Staebler-Wronski effect common in amorphous silicon solar cells will not appear in HJT solar cells. At the same time, the N-type silicon wafer used in the HJT battery has phosphorus as the dopant, and there is almost no light-induced attenuation phenomenon.

5. Thinning can be developed: the process temperature of HJT battery is low, the upper and lower surface structures are symmetrical, and there is no mechanical stress, so it can be thinned smoothly; in addition, after research, for N-type battery with high minority carrier life (SRV<100cm/s) For silicon substrates, the thinner the sheet, the higher the open circuit voltage can be obtained.

Although the technology of heterojunction solar cells is so good, it has not been widely used in the market. The main reason is the cost factor. One is the high price of production equipment, and the other is expensive consumables.

The power of a photovoltaic module is equal to the product of the effective cell area in the module, the intensity of solar radiation and the efficiency of the cell. Therefore, when heterojunction cells replace PERC cells in the future, higher power components will be created, which will bring lower cost per watt and cost per kilowatt-hour to power investors.