Heat Strengthening Glass Superstrate for Thin Film Photovoltaics
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Thin glass substrates used in cadmium telluride photovoltaic modules are susceptible to breakage due to reduced strength, which limits their efficiency and cost-effectiveness for large-scale solar power generation.
Innovation Solution
A process involving heating and quenching the glass substrate with an inert gas to create compressive stresses, increasing its strength and reducing thermal stress susceptibility, while also enhancing the efficiency of the photovoltaic device by increasing grain size and intermixing of thin film layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If thin glass substrates are used to reduce cost and improve light absorption, then manufacturing cost decreases and light absorption efficiency improves, but glass strength and breakage resistance deteriorate
Solution Approach 1:
The patent applies heat treatment parameters (heating to anneal temperature followed by rapid quenching) to change the physical state of the glass substrate, creating compressive stresses that strengthen the glass without changing its thickness or composition
Solution Approach 2:
The glass substrate undergoes phase transition during heating to anneal temperature and subsequent rapid cooling, which transforms the internal stress state of the glass and creates surface compressive stresses that enhance strength and breakage resistance
2Ease of manufacture
If thin glass substrates are used, then manufacturing cost decreases and light absorption efficiency improves, but susceptibility to breakage increases
Solution Approach 1:
By changing the thermal parameters (heating to anneal temperature and rapid quenching), the glass substrate acquires enhanced mechanical properties, allowing thin glass to maintain both low cost and high breakage resistance
3Productivity
If thin glass substrates are used to allow more light transmission, then photovoltaic efficiency improves, but structural integrity and strength deteriorate
Solution Approach 1:
The patent uses thermal parameter changes (annealing and quenching) to fundamentally alter the mechanical properties of the glass substrate, enabling thin glass to simultaneously achieve high light transmission and structural integrity
Solution Approach 2:
The phase transition of glass during controlled heating and rapid cooling creates internal stress patterns that enhance structural integrity while maintaining the thin profile needed for optimal light transmission in photovoltaic applications
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 process strengthens the glass substrate, reduces breakage risk, and improves the efficiency and reliability of the photovoltaic device, allowing for the use of thinner, less expensive glass without compromising performance.
Implementation Method 1
quenching the glass substrate with a quenching gas to cool the glass substrate to a quenched temperature in less than 10 seconds
Implementation Method 2
heating the substrate to an anneal temperature to anneal the cadmium telluride layer
Data Source
AI summary
Process and apparatus are generally provided for forming a thin film photovoltaic device. In one particular embodiment, the process includes: depositing a photovoltaic absorber layer on a glass substrate; heating the glass substrate to an anneal temperature; and quenching the glass substrate to cool the glass substrate to a quenched temperature in less than 10 seconds. The quenched temperature can be about 85° C. to about 200° C. less than the anneal temperature. The quenching atmosphere can have a quenching pressure of about 1 torr or more and can include an inert gas.