Fullerene Self-Assembled Monolayer Solar Cell Efficiency

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Solution Overview

Problem

Conventional self-assembled monolayers in organic thin-film solar cells fail to achieve sufficient photoelectric conversion efficiency due to inadequate electron-accepting properties and uniformity on the electron transport layer surface.

Innovation Solution

A solar cell configuration incorporating a self-assembled monolayer with a fullerene-containing compound, featuring a fullerene portion, an absorption group to metal oxides, and a bivalent aromatic hydrocarbon and organic group as a bond, enhancing electron transport and density on the electron transport layer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional self-assembled monolayer is used between the electron transport layer and photoelectric conversion film, then the device complexity is reduced, but the photoelectric conversion efficiency is insufficient due to inadequate electron-accepting properties and poor uniformity on the electron transport layer surface

Engineering Contradiction:

Improvephotoelectric conversion efficiencyVSAvoidself-assembled monolayer material complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses a composite self-assembled monolayer comprising a first monolayer formed from a silane-based compound on the metal oxide electron transport layer, and a second monolayer formed from a fullerene-based compound on the first monolayer. This composite structure combines the adhesion benefits of silane with the electron-accepting properties of fullerene, achieving both good uniformity and high photoelectric conversion efficiency without requiring a single complex material

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The self-assembled monolayer is divided into two functional segments: the first monolayer (silane-based) provides strong bonding to the metal oxide surface and ensures uniform coverage, while the second monolayer (fullerene-based) provides excellent electron-accepting properties. This segmentation allows each layer to optimize its specific function, resolving the contradiction between simplicity and performance

Inventive Principle:

Principle #1Segmentation

2Manufacturing precision

If the self-assembled monolayer is required to be excellent in electron-accepting property and uniform formation, then the manufacturing precision requirement increases, but conventional materials cannot satisfy these requirements

Engineering Contradiction:

Improveuniformity of self-assembled monolayer formationVSAvoidease of forming self-assembled monolayer

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The first silane-based monolayer is formed as a preliminary layer on the metal oxide electron transport layer before forming the fullerene-based second monolayer. This preliminary action creates a uniform, adhesive surface that facilitates the subsequent formation of the fullerene layer, ensuring both good uniformity and ease of manufacture for the complete monolayer structure

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The silane-based first monolayer acts as an intermediary layer between the metal oxide electron transport layer and the fullerene-based second monolayer. It provides a surface with appropriate properties that enables uniform formation of the fullerene layer while maintaining ease of the overall manufacturing process

Inventive Principle:

Principle #24Intermediary (Mediator)

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

Improves photoelectric conversion efficiency by controlling the energy level and morphology of the photoelectric conversion layer, leading to increased electron collection efficiency and reduced defects in the self-assembled monolayer.

Implementation Method 1

a self-assembled monolayer provided on the electron transport layer... The self-assembled monolayer includes a fullerene-containing compound... enhancing electron transport

Methodology Applied

Scientific EffectElectron transport: Conduction (electrical)

Implementation Method 2

The self-assembled monolayer interposed between the electron transport layer and the photoelectric conversion film is required to be excellent itself in electron-accepting property

Methodology Applied

Scientific EffectElectron acceptance: Absorption (physical)

Implementation Method 3

a photoelectric conversion layer provided on the self-assembled monolayer and including a p-type semiconductor and an n-type semiconductor

Methodology Applied

Scientific EffectPhotoelectric conversion: Photovoltaic Effect

Data Source

PatentUS10446757B2Solar cell

Publication Date: 2019.10.15 KK TOSHIBA

AI summary

An solar cell of an embodiment includes a first electrode, an electron transport layer containing a metal oxide, a self-assembled monolayer, a photoelectric conversion layer including a p-type semiconductor and an n-type semiconductor, and a second electrode. The self-assembled monolayer includes a fullerene-containing compound having a fullerene portion including a fullerene or a fullerene derivative, an absorption group to the metal oxide, and a bond group bonding the fullerene portion and the absorption group. The bond group contains a bivalent aromatic hydrocarbon group and a bivalent organic group which includes a carbon atom chain having 1 to 18 single-bonded carbon(s) or an atom chain in which a part of the carbon atom chain is substituted by at least one element selected from oxygen, nitrogen, and sulfur, as a main chain.