Hydrazine-Free Selenium Ink for CIGS Photovoltaic Deposition

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Solution Overview

Problem

Conventional methods for depositing selenium in the manufacture of CIGS materials, such as vacuum-based processes, are costly and have low throughput, and existing solution-based methods using hydrazine or hydrazinium precursors pose safety risks due to their toxicity and explosion hazards.

Innovation Solution

A selenium ink comprising a chemical compound with the formula RZ-Se^x-Z'R' stably dispersed in a nitrogen-containing liquid carrier, which is hydrazine and hydrazinium free, is developed for stable dispersion and deposition on substrates, using a method that involves combining selenium with an organic chalcogenide and a nitrogen-containing solvent to produce a reaction product that is both stable and safe.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If vacuum-based processes (vacuum-evaporation, sputtering, chemical vapor deposition) are used to deposit selenium, then deposition quality is maintained, but throughput is low and manufacturing cost is high

Engineering Contradiction:
ImprovethroughputVSAvoidmanufacturing cost
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The patent replaces vacuum-based mechanical deposition processes with a solution-based chemical deposition process. Selenium is delivered dissolved in a liquid carrier solution, eliminating the need for vacuum equipment and enabling simple solution processing methods like spin-coating or dispensing, thereby dramatically increasing throughput and reducing manufacturing costs

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the physical state of selenium from solid/ vapor to dissolved state in liquid carrier. This parameter change enables solution-based processing at ambient or near-ambient conditions, replacing high-vacuum and high-energy processes with low-cost solution processing

Inventive Principle:
Principle #35Parameter changes

2Productivity

If hydrazine or hydrazinium precursors are used in solution-based selenium deposition, then deposition capability is achieved, but safety risks increase due to toxicity and explosion hazards

Engineering Contradiction:
ImprovethroughputVSAvoidsafety risks
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent extracts and removes the harmful hydrazine and hydrazinium components from the deposition system. By using alternative selenium sources dissolved in liquid carriers without hydrazine, the invention eliminates the explosion and toxicity hazards while maintaining solution-based deposition capabilities

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent converts the harmful properties of hydrazine-based systems into a safe alternative by using selenium sources that can be dissolved in liquid carriers without requiring hydrazine. This transforms a hazardous process into a safe one while maintaining the high-throughput solution-based deposition advantage

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 selenium ink enables a cost-effective, high-throughput deposition of selenium on substrates without the safety risks associated with hydrazine or hydrazinium, facilitating the large-scale production of CIGS materials for photovoltaic cells and other semiconductor devices.

Implementation Method 1

a selenium ink comprising a chemical compound having a formula RZ-Se x -Z'R' stably dispersed in a liquid carrier

Methodology Applied
Scientific EffectDispersion: Dispersion (of waves)

Implementation Method 2

using the selenium ink to deposit selenium on a substrate

Methodology Applied
Scientific EffectDeposition: Deposition (physical)

Data Source

PatentEP2287115B1Dichalcogenide selenium ink and methods of making and using same
Publication Date: 2014.03.05 DUPONT ELECTRONIC MATERIALS INT LLC

AI summary

A selenium ink comprising a chemical compound having a formula RZ-Sex-Z'R' stably dispersed in a liquid carrier is provided, wherein the selenium ink is hydrazine free and hydrazinium free. Also provided are methods of preparing the selenium ink and of using the selenium ink to deposit selenium on a substrate for use in the manufacture of a variety of chalcogenide containing semiconductor materials, such as, thin film transistors (TFTs), light emitting diodes (LEDs); and photoresponsive devices (e.g., electrophotography (e.g., laser printers and copiers), rectifiers, photographic exposure meters and photovoltaic cells) and chalcogenide containing phase change memory materials.