Amorphous Oxide Mediator for Solar Cell Surface Passivation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current solar cell designs face challenges in enhancing conversion efficiency due to limitations in the design of layers and electrodes, which affect the overall performance and efficiency of solar energy conversion.
Innovation Solution
A solar cell design featuring a semiconductor substrate with an uneven surface, a passivation layer, and an oxide layer, where the passivation layer has varying thicknesses on convex and concave portions, and the oxide layer is made of amorphous oxide, improving surface passivation and light-receiving efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a passivation layer is formed directly on an uneven semiconductor substrate surface, then surface coverage is improved, but surface defects and recombination losses increase due to varying thickness and poor interface quality
Solution Approach 1:
An oxide layer is introduced as an intermediary between the uneven semiconductor substrate and the passivation layer. This intermediate oxide layer conforms to the uneven substrate surface topology, providing a buffer that prevents direct contact between the passivation layer and substrate defects, thereby reducing recombination losses while maintaining complete surface coverage.
Solution Approach 2:
The oxide layer is formed with varying thickness that locally adapts to the uneven substrate surface topology. The layer thickness is optimized at different locations (thinner on convex portions, thicker on concave portions) to ensure complete coverage while maintaining good interface quality and reducing surface defects across the entire substrate surface.
2Reliability
If the passivation layer thickness is increased to improve surface coverage on uneven surfaces, then coverage is improved, but carrier movement and conversion efficiency deteriorate due to excessive thickness
Solution Approach 1:
The oxide layer serves as a mediator that enables complete surface coverage at reduced passivation layer thickness. By providing the intermediate buffer layer, the system achieves full coverage on uneven surfaces without requiring excessive passivation layer thickness, thus maintaining good carrier movement properties and energy conversion efficiency.
Solution Approach 2:
The thickness parameter of the passivation layer is optimized by introducing the oxide layer intermediate. This allows the passivation layer to be thinner than it would need to be without the oxide layer, while still achieving complete coverage. The oxide layer thickness is also controlled to be appropriate for the given substrate unevenness, optimizing both coverage and carrier transport.
3Productivity
If the semiconductor substrate surface is made uneven to reduce reflection, then light-receiving efficiency is improved, but surface defects and interface quality worsen
Solution Approach 1:
The oxide layer converts the harmful effect of substrate surface unevenness into a beneficial configuration. Instead of trying to eliminate the unevenness (which would reduce light-trapping efficiency), the oxide layer is formed to conform to and accommodate the uneven topology, transforming the potential defect source into an optimized intermediate structure that reduces reflection while managing surface defects.
Solution Approach 2:
The oxide layer acts as an intermediary that decouples the light-trapping function (achieved through substrate unevenness) from the passivation function (requiring smooth interfaces). This intermediate layer allows the substrate to maintain its light-trapping unevenness while the oxide provides a conformal, defect-reducing interface for the passivation layer.
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 proposed design enhances solar cell efficiency by reducing surface defects, suppressing crystallinity, and improving carrier movement, leading to increased photoluminescence intensity and overall energy conversion efficiency.
Implementation Method 1
the oxide layer including amorphous oxide... suppressing crystallinity
Implementation Method 2
an uneven portion being located on at least one of a front surface or a rear surface... improving light-receiving efficiency
Implementation Method 3
the passivation layer having varying thicknesses on convex and concave portions... improving carrier movement
Implementation Method 4
leading to increased photoluminescence intensity and overall energy conversion efficiency
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A solar cell (100) includes: a semiconductor substrate (110) including an uneven portion (112), the uneven portion being located on at least one of a front surface or a rear surface of the semiconductor substrate; a passivation layer (52, 54) disposed on the uneven portion; and an oxide layer (SO) disposed between the passivation layer and the uneven portion of the semiconductor substrate, the oxide layer including amorphous oxide.