Low-Temperature Solar Cell Metal Oxide Layer

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Solution Overview

Problem

Existing solar cells face challenges such as solvent evaporation, water penetration, incomplete pore filling, low hole mobility, and the need for high-temperature processing, which restricts the use of flexible substrates and increases costs.

Innovation Solution

A low-temperature manufacturing process for solar cells using a metal oxide layer with a thickness of 200 nm or less, applied on a current collector or optional compact metal oxide underlayer, combined with a sensitizer layer and counter electrode, without the need for sintering, allowing for the use of plastic substrates and achieving high power conversion efficiencies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If high-temperature sintering steps are employed for the compact layer and porous electron-transporting oxide film, then device efficiency is improved, but the use of flexible plastic substrates is restricted

Engineering Contradiction:

Improvedevice efficiencyVSAvoiduse of flexible substrates

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The invention changes the temperature parameter from high-temperature sintering (500°C) to low-temperature processing (below 300°C). This parameter change enables the use of flexible plastic substrates while maintaining device efficiency through optimized low-temperature deposition processes for the metal oxide layer and perovskite sensitizer

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention replaces the thermal sintering mechanism with alternative low-temperature deposition mechanisms such as chemical bath deposition, spin coating, or atomic layer deposition. These methods achieve crystallization and densification without requiring high-temperature furnaces, enabling flexible substrate compatibility

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If liquid electrolytes are used in solar cells, then power conversion efficiency is improved, but solvent evaporation and water penetration problems occur

Engineering Contradiction:

Improvepower conversion efficiencyVSAvoidsolvent evaporation and water penetration

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention introduces a solid-state metal oxide layer as an intermediary between the perovskite sensitizer and the electrode. This solid-state mediator provides efficient charge transport while eliminating the need for liquid electrolytes, thereby preventing solvent evaporation and water penetration issues

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention changes the physical state parameter of the electrolyte from liquid to solid. By using a solid-state metal oxide layer with appropriate band structure, the system maintains high charge transport efficiency while eliminating the harmful effects associated with liquid electrolytes

Inventive Principle:

Principle #35Parameter changes

3Ease of manufacture

If organic hole conductors are used to fill pores in mesoporous films, then device assembly is simplified, but incomplete pore filling and low hole mobility are observed

Engineering Contradiction:

Improvedevice assemblyVSAvoidhole mobility

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The invention uses a composite structure consisting of a metal oxide layer combined with a perovskite sensitizer. The metal oxide provides the porous scaffold for complete pore filling, while the perovskite material provides high hole mobility, combining the advantages of both materials to overcome their individual limitations

Inventive Principle:

Principle #40Composite materials

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 enables the production of solar cells with high power conversion efficiencies while reducing processing temperatures below 300°C, facilitating the use of flexible substrates and lowering production costs.

Implementation Method 1

a metal oxide layer, having a thickness of 200 nm or less

Methodology Applied

Scientific EffectElectron transport: Conduction (electrical)

Implementation Method 2

a sensitizer layer on the metal oxide layer

Methodology Applied

Scientific EffectPhoton absorption: Absorption (EM radiation)

Implementation Method 3

conversion of solar energy to electrical current

Methodology Applied

Scientific EffectPhotoexcitation: Photoelectric Effect

Implementation Method 4

The conversion of solar energy to electrical current using thin film third generation photovoltaics (PV)

Methodology Applied

Scientific EffectPhotovoltaic conversion: Photovoltaic Effect

Data Source

PatentUS10332689B2Solar cell and process for producing the same

Publication Date: 2019.06.25 ECOLE POLYTECHNIQUE FEDERALE DE LAUSANNE (EPFL)

AI summary

The present invention relates to photoanodes, solar cells and methods and processes for producing the same. In some embodiments, the solar cells of the invention can do without a sintered nanoporous scaffold layer, making it possible to produce the solar cells in low-temperature procedures. In some embodiments, the invention encompasses organic-inorganic perovskite sensitizers, deposited on a smooth metal oxide layer. In some embodiments, the organic-inorganic perovskite sensitizers are deposited in a two-step sequential process.