Hole-Transporting Layer Rc(50) Control for Solar Cell Leakage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Solid dye-sensitized solar cells face issues with current leakage between the electron-transporting and hole-transporting layers, particularly when transitioning from high to low illuminance light, leading to reduced photoelectric conversion efficiency.
Innovation Solution
The photoelectric conversion element is designed with a hole-transporting layer where the ratio of projected areas exceeding a certain height (Rc(50)) is minimized, ensuring the second electrode's thickness is sufficient to prevent current leakage, maintaining high output even under low illuminance conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a solid hole-transporting layer is used in a solid dye-sensitized solar cell, then the device structure is simplified and manufacturing is easier, but current leakage occurs between the electron-transporting and hole-transporting layers leading to reduced output
Solution Approach 1:
The invention applies local quality by creating a dense layer with different properties than the rest of the hole-transporting layer. Specifically, a dense layer of titanium oxide is formed between the transparent conductive film and the electron-transporting layer using a solution including a titanium compound, while the remainder of the hole-transporting layer uses a solid hole-transporting material. This localized dense structure prevents current leakage at the critical interface without compromising the overall solid-state structure and manufacturing simplicity.
Solution Approach 2:
The invention uses an intermediary approach by introducing a dense layer of titanium oxide as a mediator between the transparent conductive film and the electron-transporting layer. This intermediate dense layer acts as a barrier that prevents direct contact and current leakage between the electron-transporting and hole-transporting layers, while still allowing the solid-state structure to function effectively.
2Reliability
If the hole-transporting layer is made thicker to prevent current leakage, then current leakage is reduced, but the photoelectric conversion efficiency decreases due to increased resistance
Solution Approach 1:
The invention resolves this contradiction by applying local quality - creating a dense layer with specific protective properties at the critical interface region where current leakage occurs, while the rest of the hole-transporting layer maintains optimal thickness for charge transport. The dense layer of titanium oxide is formed only between the transparent conductive film and the electron-transporting layer, providing leakage prevention without requiring the entire hole-transporting layer to be thicker.
Solution Approach 2:
The invention segments the hole-transporting layer into two distinct parts: a dense layer of titanium oxide at the interface with the transparent conductive film, and the remaining portion with solid hole-transporting material. This segmentation allows each part to perform its specific function - the dense layer prevents current leakage while the main body maintains efficient charge transport.
3Power
If a dense layer of titanium oxide is formed between the transparent conductive film and electron-transporting layer to prevent current leakage, then output is maintained, but the device complexity increases
Solution Approach 1:
The invention merges the functions of the dense protective layer and the hole-transporting layer into a single integrated structure. The dense layer of titanium oxide is formed using a solution including a titanium compound that is applied to the same substrate as the hole-transporting material, combining the protective barrier function with the charge transport function in one unified layer structure rather than requiring separate components.
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 configuration effectively suppresses current leakage and maintains high output performance across varying light conditions, ensuring stable power generation with both high and low illuminance light exposure.
Implementation Method 1
solar cells have become more and more important as alternative energy for fossil fuels and as a measure against global warming
Data Source
AI summary
Provided is a photoelectric conversion element including a first electrode, an electron-transporting layer, a hole-transporting layer, and a second electrode, wherein the hole-transporting layer and the second electrode are in contact with each other, and the hole-transporting layer satisfies the following formula:0%<Rc(50)≤0.75%where an average thickness of the hole-transporting layer is determined as X (nm), and Rc(50) is a ratio of an area of projected parts that are projected from a standard line towards the second electrode, where the standard line is present at a position that is away, by X+50 (nm), from an opposite surface of the hole-transporting layer to a surface of the hole-transporting layer in contact with the second electrode.