Application of rapid temperature rise and fall annealing furnace in the photovoltaic industry

The rapid temperature rise and fall annealing furnace (RTP) is widely used and critical in the photovoltaic industry, with its core value reflected in improving battery efficiency, optimizing film quality, accelerating process iteration, and reducing production costs. The following is a detailed analysis of specific application scenarios and technological advantages:

1. Crystalline silicon solar cells: improving photoelectric conversion efficiency
Repair after ion implantation
Function: Repair the lattice damage caused by ion implantation on the wafer, activate doping elements (such as boron and phosphorus), and form conductive regions.
Advantages: Rapid annealing can accurately control the diffusion depth of doping elements, avoid excessive impurity diffusion caused by traditional annealing, and improve the open circuit voltage (Voc) and fill factor (FF) of the battery.
Case: A company adopts RTP technology to improve the efficiency of single-crystal PERC cells, approaching the theoretical limit.
Surface passivation treatment
Function: To form an oxide layer or a silicon nitride passivation layer on the surface of silicon wafers through rapid annealing, reducing carrier recombination losses.
Advantages: The extremely short heat treatment time (usually a few seconds) can prevent excessive growth of passivation layer, maintain surface flatness, and improve battery short-circuit current (Jsc).

2. Thin film solar cells: optimizing film quality and performance
CIGS (Copper Indium Gallium Selenide) Thin Film Battery
Function: In the selenization process, RTP achieves uniform distribution of selenium through rapid annealing, forming a high-quality CIGS absorption layer.
Advantage: The extremely short heat treatment time can reduce selenium volatilization and improve battery conversion efficiency. For example, a research institute in Germany has adopted RTP technology to improve the efficiency of CIGS cells, approaching the level of crystalline silicon cells.
Process details: The selenization temperature is usually controlled at 500-550 ℃, the annealing time is 5-10 minutes, and the atmosphere is a mixture of nitrogen and selenium vapor.
Perovskite solar cells
Function: In the annealing process, RTP rapidly removes solvents and promotes grain growth, forming dense perovskite films.
Advantages: Accurate temperature control (such as 100-150 ℃) can suppress grain coarsening, improve film stability and optoelectronic performance. For example, a certain photovoltaic company utilizes RTP technology to improve the efficiency of perovskite/silicon stacked cells.
Process innovation: Adopting segmented annealing (such as first removing solvents at low temperatures and then promoting crystallization at high temperatures) can further optimize the morphology of the thin film.

3. Photovoltaic material research and development: accelerating the iteration of new materials
Nanostructure materials
Function: Control the size and distribution of nanoparticles through rapid annealing, and regulate the material’s light absorption and carrier transport properties.
Case: In quantum dot solar cells, RTP technology can achieve precise control of quantum dot size (such as 2-5 nanometers), expand the light absorption range to the near-infrared region, and improve battery efficiency.
Transparent conductive oxide (TCO)
Function: In the preparation of TCO thin films (such as ITO, AZO), RTP improves the crystallinity of the film and reduces the resistivity through rapid annealing.
Advantages: Compared with traditional annealing, RTP can reduce the resistivity of TCO films to the order of 10 ⁻⁴Ω· cm while maintaining high transmittance.

4. Photovoltaic module manufacturing: improving production efficiency and yield rate
Cell bonding and densification
Function: In the welding or laminating process of battery cells, RTP eliminates internal stress through rapid annealing and improves the mechanical stability of components.
Case: In the manufacturing of double glass components, RTP technology can reduce the lamination temperature to 120-150 ℃, shorten the annealing time to 5 minutes, and reduce the risk of glass bending and cell cracking.

5. Technological Trends: Intelligence and Green Manufacturing
Intelligent automation control
Function: Realize full process automation control through upper computer and Ethernet communication technology, support temperature curve preset, real-time data monitoring, and abnormal alarm.
Case: The annealing furnace is equipped with a built-in exhaust gas treatment system, which ensures emissions meet international environmental standards through multi-stage filtration and adsorption technology.
Modular and flexible production
Design: The equipment adopts a modular compact structure, supports nitrogen or dry air clean control, and is suitable for clean workshop environments below 10000 levels.
Advantages: The design of independent transmission units and heating modules facilitates quick maintenance and upgrades, reduces long-term operating costs, and supports flexible layout of production lines.