CIGS Absorber Layer Spray Pyrolysis Deposition
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Solution Overview
Problem
Conventional photovoltaic device production methods, particularly those using copper indium gallium selenide (CIGS) absorber layers, face high production costs and low efficiency due to expensive vacuum-based deposition processes and inefficiencies in material utilization, as well as challenges with solution-based approaches that often result in low efficiencies and the introduction of toxic substances.
Innovation Solution
A low-cost, solution-based spray pyrolysis method using a precursor solution of metal chalcogenides dissolved in hydrazine or hydrazine-like solvents is employed to deposit CIGS absorber layers, avoiding toxic substances and high-temperature annealing, and allowing for better grain growth and improved device efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If vacuum-based deposition processes are used to produce CIGS absorber layers, then high conversion efficiency can be achieved, but production cost increases significantly
Solution Approach 1:
The patent replaces vacuum-based mechanical deposition processes with a solution-based spray pyrolysis method. Instead of using vacuum chambers and evaporated metal sources, the invention uses liquid precursor solutions containing metal chalcogenides that are sprayed onto heated substrates, eliminating expensive vacuum equipment while achieving comparable conversion efficiencies through chemical deposition mechanisms
Solution Approach 2:
The patent changes the physical and chemical parameters of the deposition process by transitioning from vapor-phase metal sources in vacuum to liquid-phase metal chalcogenide precursors. The substrate temperature is optimized to 300-600°C for spray pyrolysis, and the precursor solution composition is carefully controlled to achieve the desired CIGS stoichiometry and crystal structure, thereby maintaining high efficiency at lower cost
2Manufacturing precision
If vacuum-based deposition processes are used, then CIGS absorber layers can be formed with desired composition, but material utilization efficiency decreases due to deposition on vacuum walls
Solution Approach 1:
The patent replaces the vacuum evaporation mechanism with a direct liquid-to-solid deposition mechanism. The precursor solution is sprayed directly onto the substrate surface where it decomposes and forms the CIGS layer, eliminating the problem of material deposition on vacuum chamber walls and significantly improving material utilization efficiency
Solution Approach 2:
The precursor solution is designed to decompose and react self-completely on the heated substrate surface during spray pyrolysis. The metal chalcogenides in the solution automatically react with each other and with ambient chalcogen to form the desired CIGS compound, minimizing material loss without requiring additional material input to compensate for vacuum wall deposition
3Ease of manufacture
If solution-based deposition processes are used to reduce costs, then production cost decreases, but device efficiency and process complexity face challenges
Solution Approach 1:
The patent optimizes solution-based deposition by carefully controlling precursor solution composition, spray rate, substrate temperature (300-600°C), and ambient atmosphere. These parameter optimizations enable the formation of high-quality CIGS absorber layers with appropriate bandgap and crystalline structure, achieving device efficiencies comparable to vacuum methods while maintaining the cost advantages of solution processing
Solution Approach 2:
The patent employs controlled atmospheric conditions during spray pyrolysis to prevent unwanted oxidation and ensure complete reaction of the precursor materials. By managing the ambient environment (inert or controlled oxygen partial pressure), the process achieves high device efficiency and material quality while maintaining the simplicity and low cost of solution-based processing
4Ease of manufacture
If conventional solution-based processes are used, then production cost is reduced, but toxic substances and impurities are introduced during processing
Solution Approach 1:
The patent uses metal chalcogenide precursors instead of traditional metal salts or organometallic compounds. These chalcogenide-based precursors decompose cleanly during spray pyrolysis to form pure CIGS without introducing carbon, chlorine, or other organic impurities, thereby eliminating toxic substances while maintaining the low-cost advantage of solution processing
Solution Approach 2:
The patent converts the potential harm of using solution-based processing (which can introduce impurities) into a benefit by selecting precursor materials that decompose cleanly. The metal chalcogenides in the solution are designed to decompose completely and react to form pure CIGS absorber layers, transforming what could be a source of contamination into a purification mechanism that eliminates toxic substances
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
This method enables the production of high-efficiency, large-area CIGS solar cells with reduced material costs and improved performance by eliminating impurities and facilitating better control over film composition and electrical properties, achieving efficiencies up to 10.3% without the need for toxic selenization processes.
Implementation Method 1
Spray pyrolysis in an inert environment is used to deposit the precursor solution onto a substrate to form a metal chalcogenide layer on the substrate
Implementation Method 2
A substrate is provided. A metal chalcogenide layer is formed on the substrate
Data Source
AI summary
Techniques for fabricating a photovoltaic device having a chalcopyrite absorber layer, such as a copper indium gallium selenide/sulfide (CIGSS) absorber layer, are provided. In one aspect, a method for fabricating a photovoltaic device is provided. The method includes the following steps. A precursor solution of metal chalcogenide dissolved in hydrazine or a hydrazine-like solvent is formed. Spray pyrolysis in an inert environment is used to deposit the precursor solution onto a substrate to form a metal chalcogenide layer on the substrate. A buffer layer is formed adjacent to a side of the metal chalcogenide layer opposite the substrate. A transparent conductive contact is formed adjacent to a side of the buffer layer opposite the metal chalcogenide layer.