1. Technical Background and Objectives of PV Glass Coating
In photovoltaic modules, PV glass serves as the front encapsulation material, directly determining light incidence efficiency and long-term module stability.
With the advancement of high-efficiency cell technologies such as TOPCon, HJT, and BC, higher requirements are placed on PV glass coatings, including:
Higher visible light transmittance
Lower surface reflection losses
Excellent environmental durability and long-term reliability
Batch consistency for large-area module production
Proper coating solutions can significantly increase module power output without altering cell architecture.
2. Mainstream Coating Technology Routes for PV Glass
2.1 Anti-Reflection (AR) Coatings
Anti-reflection coatings are the most widely applied functional layers on PV glass. Their primary objective is to reduce surface reflectance and enhance transmittance.
Common coating materials include:
SiO₂
SiNx
Multilayer dielectric stacks
Typical process routes include:
Magnetron sputtering deposition
CVD or hybrid PVD+CVD processes
Through optical stack design, reflectance in the visible spectrum is significantly reduced, improving overall energy conversion efficiency.
2.2 Self-Cleaning and Anti-Soiling Coatings
In long-term outdoor environments, dust and contaminants degrade optical performance.
By depositing:
Super-hydrophilic coatings
Low surface energy functional layers
PV glass can achieve self-cleaning performance through natural rainfall, reducing maintenance costs.
2.3 Weather-Resistant and Protective Coatings
PV modules must operate reliably under high temperature, humidity, UV exposure, and abrasive conditions.
By introducing dense protective layers above AR coatings, the following properties can be enhanced:
Damp heat resistance
UV aging resistance
Mechanical stability
3. Key Process Control Considerations
3.1 Precise Control of Film Thickness and Refractive Index
AR performance is highly sensitive to thickness and refractive index matching.
This requires:
Quartz crystal monitoring systems
Optical in-situ monitoring
Closed-loop control algorithms
to ensure uniform optical performance across large-area glass substrates.
3.2 Film Density and Adhesion
High-energy deposition and ion-assisted technologies improve film density and interfacial adhesion, preventing long-term coating degradation.
3.3 Uniformity Control for Large-Area Glass
As module sizes continue to increase, coating uniformity becomes more challenging.
Through:
Multi-target configurations
Optimized magnetic field designs
Controlled glass motion and takt time
stable and repeatable mass production can be achieved.
4. Mass Production Stability and Reliability Verification
PV glass coatings must undergo rigorous reliability testing, including:
Damp heat testing (85°C / 85% RH)
UV aging tests
Salt spray tests
Mechanical abrasion tests
to ensure stable performance throughout the 25-year service life of photovoltaic modules.
5. Conclusion
Photovoltaic glass coating is not a single-process challenge but a system-level engineering task involving material selection, optical stack design, equipment capability, and process control.
With mature and scalable vacuum coating solutions, PV modules can achieve higher power output while maintaining long-term reliability.
–This article was published by vacuum coating equipment manufacturer Zhenhua Vacuum
Post time: Dec-26-2025