Application of laboratory tubular PECVD electric furnace in the photovoltaic industry

The laboratory tubular PECVD electric furnace is widely and crucially used in the photovoltaic industry, mainly reflected in the following aspects:

1. Core function: Efficient deposition of anti reflective film
Anti reflection film deposition: A tubular PECVD electric furnace uses plasma assisted chemical vapor deposition technology to deposit silicon nitride (SiNx) anti reflection films on the surface of crystalline silicon solar cells. This thin film reduces surface reflection by adjusting its thickness and refractive index, utilizing the principle of light interference to allow more light to enter the interior of the battery, thereby improving the photoelectric conversion efficiency.
Passivation effect: The hydrogen element in SiNx thin film can passivate lattice defects on the silicon surface (such as dislocations and dangling bonds), reduce carrier recombination, improve open circuit voltage and short-circuit current, and further optimize battery performance.
Mechanical protection: The film serves as an encapsulation layer to prevent contamination or mechanical damage to the silicon wafer during subsequent processes, ensuring the integrity and reliability of the battery cell.

2. Technical advantages: low temperature, high efficiency, and precision
Low temperature process: The tubular PECVD electric furnace uses plasma to excite the reaction gas, reducing the deposition temperature to 400-500 ℃, much lower than the traditional CVD technology’s above 800 ℃. This low-temperature characteristic avoids thermal damage to silicon wafers and substrate materials at high temperatures, especially suitable for the manufacturing of thin and flexible batteries.
Efficient deposition: Radio frequency glow technology generates high-density plasma through high-frequency electric field, greatly improving reaction rate, high deposition rate, and significantly shortening production cycle.
Precise control: Adopting multi-point RF feeding, uniform air path distribution, and intelligent temperature control system to ensure good uniformity of film thickness and meet the needs of large-scale production. At the same time, various dielectric films such as SiO ₂, Si ∝ N ₄, Al ₂ O ∝ can be deposited, expanding the design space of battery structures (such as stacked batteries and back passivation batteries).

3. Application example: Improving battery performance and efficiency
PERC cell: By depositing a backside Al ₂ O ∝/SiNx laminated film, the dual functions of backside passivation and anti reflection are achieved, improving the efficiency of the cell.
TOPCon battery: Utilizing PECVD deposition of tunneling oxide layer (SiO ₂) and doped polycrystalline silicon layer to construct efficient carrier transport channels, reduce surface recombination rate, and improve open circuit voltage and short circuit current.
HJT battery: Deposition of intrinsic amorphous silicon (i-a-Si: H) at the interface of amorphous silicon/crystalline silicon heterojunction to optimize the density of interface defect states and enhance battery performance.

4. Environmental Protection and Economy: Green Manufacturing and Cost Optimization
Environmental friendliness: Low temperature technology reduces energy consumption while avoiding the emission of harmful substances at high temperatures, in line with the trend of green manufacturing in the photovoltaic industry.
Economy: Efficient sedimentation and precise control reduce material waste and rework rates, improve production efficiency and product yield, thereby reducing production costs.