Solar Cell Module Oxide Layer Prevents PID
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Solution Overview
Problem
Existing solar cell modules in MW class photovoltaic power generation systems suffer from performance degradation due to potential-induced degradation (PID) in high temperature and high humidity environments, where sodium ions from the protection glass diffuse and accumulate on the antireflection film, leading to leakage currents and degraded solar cell characteristics.
Innovation Solution
A solar cell module is designed with an oxide layer containing specific metal elements like titanium, vanadium, chromium, or manganese between the substrate and the protection glass, which shields the diffusion of sodium ions, preventing their accumulation and thus mitigating PID damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the protection glass is used in MW class photovoltaic power generation systems, then the structural support and protection function is achieved, but sodium ion diffusion occurs under high temperature and high humidity conditions leading to PID damage
Solution Approach 1:
An oxide layer containing metal elements (Ti, V, Cr, Mn, etc.) is introduced as an intermediary barrier between the protection glass and the solar cell substrate. This intermediate layer effectively blocks sodium ion diffusion from the glass to the cell, preventing PID damage while maintaining the structural support function of the protection glass.
Solution Approach 2:
The protection glass is combined with an oxide layer containing multiple metal elements to form a composite structure. This composite material system provides both the mechanical strength of the glass and the ion-blocking properties of the oxide layer, resolving the contradiction between structural support and ion diffusion prevention.
2Reliability
If the encapsulating material thickness is increased to suppress PID damage, then the insulation property is improved, but the device complexity and manufacturing cost increase
Solution Approach 1:
Instead of increasing the thickness of the encapsulating material, an oxide layer is introduced as an intermediate barrier between the protection glass and the solar cell. This approach provides effective PID suppression through the ion-blocking property of the oxide layer, avoiding the need for thicker encapsulating materials and the associated increase in device complexity.
3Reliability
If a crosslinked cured film with high volume resistivity is used as encapsulating material, then the Na+ ion diffusion is suppressed, but the manufacturing process complexity increases
Solution Approach 1:
An oxide layer is introduced as an intermediate barrier between the protection glass and the solar cell substrate. This oxide layer provides effective Na+ ion diffusion blocking, achieving the same reliability benefit as crosslinked cured films but with a simpler manufacturing process that does not require complex crosslinking chemistry.
4Reliability
If an ionomer resin layer with small water vapor permeation is added, then the Na+ ion diffusion is suppressed, but the device complexity and layer structure become more complicated
Solution Approach 1:
A single oxide layer containing metal elements is introduced as an intermediate barrier between the protection glass and the solar cell. This simplified intermediate structure provides effective ion diffusion blocking without the need for multiple functional layers (ionomer resin layer, transparent resin layer, etc.), thereby reducing device complexity while maintaining reliability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The oxide layer effectively prevents sodium ion diffusion, significantly reducing PID damage and maintaining excellent battery characteristics by forming a stable oxide barrier that suppresses ion accumulation, even under high voltage conditions.
Implementation Method 1
an oxide layer containing a metal element and silicon between a substrate and a protection glass
Data Source
AI summary
A solar cell module capable of preventing the occurrence of a PID failure in a solar photovoltaic power generation system with a MW capacity, said system being used in a high-temperature high-humidity environment; and a method for manufacturing this solar cell module. A solar cell module which comprises a protection glass material and a sealing material on a light receiving surface side of a substrate, and which also comprises an oxide layer between the substrate and the protection glass material, said oxide layer containing a metal element and silicon. It is preferable that the oxide layer contains at least one metal element selected from the group consisting of magnesium, aluminum, titanium, vanadium, chromium, manganese, zirconium, niobium and molybdenum. It is also preferable that the oxide layer has a refractive index of from 1.5 to 2.3 (inclusive) with respect to incident light having a wavelength of 587 nm.