Heterojunction (HJT) cells have revolutionized traditional cell structures, offering advantages such as high conversion efficiency, simple manufacturing processes, thin silicon wafer application, low temperature coefficient, no light-induced degradation or potential decay, and bifacial power generation. Furthermore, the conversion efficiency advantage of HJT modules significantly surpasses that of PERC. PERC's output efficiency is 10% lower than that of HJT, meaning that for the same power output, a HJT module will generate 10% more electricity than a PERC module over its entire power generation cycle.
Features and advantages of heterojunction solar cells (HJT cells)
1. No PID phenomenon: Because the upper surface of the battery is a TCO (Total Collector Oxide), the charge will not generate polarization on the TCO surface, thus eliminating the PID phenomenon. This is also confirmed by measured data. Applications and prospects of heterojunction solar cells.
2. Low-temperature manufacturing process: The processing temperature of all processes in HJT batteries is below 250°C, which avoids the high-temperature diffusion junction process with low production efficiency and high cost. Moreover, the low-temperature process allows for more precise control of the optical bandgap, deposition rate, absorption coefficient and hydrogen content of a-Si thin film, and can also avoid adverse effects such as thermal stress caused by high temperature.
3. High efficiency: HJT cells have been breaking world records for mass-produced cell conversion efficiency. HJT cells are 1-2% more efficient than P-type monocrystalline silicon cells, and the difference is gradually increasing.
4. Applications and Prospects of High Light Stability Heterojunction Solar Cells: HJT solar cells do not exhibit the Staebler-Wronski effect commonly found in amorphous silicon solar cells. Furthermore, the N-type silicon wafers used in HJT cells, with phosphorus as the dopant, show virtually no light-induced degradation.
5. Can be developed towards thinner profiles: HJT cells have low process temperatures, symmetrical upper and lower surface structures, and no mechanical stress, which can be easily achieved in thinner profiles; in addition, research has shown that for N-type silicon substrates with high minority carrier lifetime (SRV<100cm/s), the thinner the wafer, the higher the open circuit voltage can be obtained.
Although heterojunction solar cells have such advanced technology, they have not yet been widely adopted in the market, mainly due to cost factors, namely, the high price of production equipment and the high cost of consumables.
The power output of a photovoltaic (PV) module is equal to the product of the effective cell area, solar radiation intensity, and cell efficiency. Therefore, replacing PERC cells with heterojunction cells in the future will result in higher-power modules, leading to lower cost per watt and levelized cost of electricity (LCOE) for power investors.
