1. How to judge the future competitiveness of the three major battery new technologies - the balance between efficiency and cost

Technical principle: The core structure of photovoltaic cells is PN junction and electrodes. The efficiency loss is mainly divided into optical and electrical losses. HJT&TOPCon reduces electrical losses, and IBC reduces optical losses.

Efficiency: IBC (overlay)>TOPCon (double-sided)>HJT

TOPCon: The passivation contact without opening is realized, the POLO structure can be upgraded in the future, and the theoretical limit of double-sided TOPCon can reach 28.7%.

HJT: The crystalline silicon/amorphous silicon heterojunction forms a PN junction, and an intrinsic amorphous silicon passivation film is plated between the crystalline silicon and the amorphous silicon, and the theoretical limit can reach 28.5%.

IBC: The electrodes are placed on the backside to reduce the loss of light shading, and the tunnel oxide layer is used for electron transmission. In the future, TOPCon or HJT technology can be superimposed, and the upper limit of efficiency after superposition can reach 29.1%.

Cost: IBC (P type)>TOPCon (single side)>HJT

Sub-routes: TOPCon relies on reducing silver consumption and thinning; HJT relies on localization of low-temperature silver paste, reducing silver consumption, thinning, and equipment cost; IBC relies on mask process optimization, thinning, and equipment cost reduction.

Sensitivity analysis: For each 1pct increase in efficiency, yield, and CTM, the cost can be reduced by 14, 1, and 3 points, respectively, and the wafer thickness can be reduced by 10 μ, resulting in a 4-point cost reduction.

Mass production: TOPCon (single side)>IBC (P type)>HJT

TOPCon: 29GW is already in production, and it is planned to exceed 40GW in 22 years. The average efficiency of leading mass production is 24.5%.

HJT: 5GW is already in production, and it is planned to exceed 9GW in 22 years. The average efficiency of leading mass production is 24.5%.

IBC: 0.2GW is already in production, and it is planned to exceed 8.5GW in 22 years. The average efficiency of leading mass production is 24%.

Conclusion: In the short term, N-type TOPCon and P-type IBC may be more cost-effective options. In the medium term, various routes coexist (HJT has great potential for efficiency improvement, and the other two have low cost). In the long run, it may transform to TBC&HBC.

2. What kind of industrial chain changes will the new cell technology bring?

Solar Cell

TOPCon: Part of the PERC production line can be used to add a tunnel oxide layer and a doped polysilicon layer. There are mainly three methods: LP preparation of polysilicon film + diffusion, LP preparation of polysilicon film + ion implantation, and PE preparation of polysilicon film + in-situ doping.

HJT: New production line but simple process flow, adding intrinsic amorphous silicon passivation layer and heterojunction structure; amorphous silicon coating technology has two routes: PECVD and CAT-CVD, and transparent conductive film (TCO) coating also has PVD There are two routes: low-temperature silver paste and RPD; low-temperature silver paste is in urgent need of localization, and HJT has greatly increased the demand for silver paste; the increase in TCO coating demand has led to a high increase in the demand for target materials.

IBC: Increase the patterning process such as backside mask and slotting, which can be combined with TOPCon and HJT to form more efficient TBC and HBC cells.

Silicon Wafer

Parameters: Different technologies have different requirements on the performance parameters and thickness of silicon wafers. For example, TOPCon requires relatively (compared to other technologies) lower resistivity and minority carrier lifetime, and IBC requires high resistivity and minority carrier lifetime.

Crystal pulling: The purity requirements of quartz crucible & carbon-carbon thermal field are increased, and the consumption of a single furnace is increased.

Slicing: diamond wire continues to develop in the direction of thinning, or there may be a technological change in replacing steel wire with tungsten wire.

Solar Panels

Adhesive film: N-type have high requirements for water resistance, POE/EPE has excellent anti-PID performance, and the permeability may be improved.