Back Contact Solar Cell Self-Aligned Doping via Oxide Mask
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing manufacturing process for solar cells is complex and costly, and the proximity of p-doped and n-doped regions leads to efficient recombination of electron-hole pairs, reducing solar energy use efficiency.
Innovation Solution
A method involving the formation of doped regions with a thicker silicon oxide layer on the substrate, using it as a self-alignment mask for ion implantation, and separating the doped regions to improve the manufacturing process and reduce costs, while maintaining high solar light use efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multiple separate processes are used to form doped regions and reflection preventing layers, then manufacturing precision can be maintained, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent combines the formation of doped regions and reflection preventing layers into a single ion implantation process. The silicon oxide layer serves as a self-aligning mask that enables both doping and reflection prevention functionality to be achieved simultaneously, eliminating the need for separate deposition and etching processes while maintaining manufacturing precision.
Solution Approach 2:
The silicon oxide layer is designed to serve multiple functions: it acts as a mask for ion implantation to form doped regions, and simultaneously serves as a reflection preventing layer. This multi-functionality reduces the number of separate manufacturing steps required while maintaining the precision needed for each function.
2Productivity
If p-doped and n-doped regions are placed close together to maximize active area, then productivity increases, but electron-hole recombination increases reducing energy efficiency
Solution Approach 1:
The patent introduces an intrinsic semiconductor layer as an intermediary between the p-doped and n-doped regions. This intrinsic layer acts as a buffer that prevents direct contact between oppositely doped regions, thereby reducing electron-hole recombination at the junction interface while allowing the doped regions to be positioned close together for maximum active area utilization.
3Manufacturing precision
If traditional multi-step processes are used for forming doped regions, then manufacturing precision can be maintained, but loss of time and manufacturing cost increase
Solution Approach 1:
The patent performs preliminary formation of the silicon oxide layer on the substrate before ion implantation. This pre-formed oxide layer serves as a self-aligning mask that automatically defines the precise locations for doped region formation during subsequent ion implantation, eliminating the need for separate photolithography and etching steps while maintaining high manufacturing precision.
Solution Approach 2:
The silicon oxide layer serves as a self-aligning mask that automatically defines the precise locations for ion implantation without requiring external alignment procedures. The mask pattern is inherently formed by the oxide deposition process itself, enabling the system to self-determine the precise positioning of doped regions and reducing the need for additional alignment and measurement steps.
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 approach simplifies the manufacturing process, reduces costs, and enhances the efficiency of solar energy conversion by effectively separating doped regions, thereby reducing recombination and improving overall solar cell performance.
Implementation Method 1
forming a silicon oxide layer on the first surface, the silicon oxide layer including a first silicon oxide layer on the first doped region and having a first thickness, and a second silicon oxide layer on a portion of the first surface undoped by the first dopant and having a second thickness that is less than the first thickness, implanting a second dopant from outside the first surface into the first silicon oxide layer and the second silicon oxide layer
Implementation Method 2
forming a second doped region adjacent the first doped region by performing heat treatment on the first silicon oxide layer, the second silicon oxide layer, and the substrate
Implementation Method 3
implanting a second dopant from outside the first surface into the first silicon oxide layer and the second silicon oxide layer
Implementation Method 4
When solar light is incident on the solar cell, that is, when photons enter into the substrate, electron-hole pairs are formed in the substrate, the generated electrons move to the n-doped region, and the generated holes move to the p-doped region. Due to the movement of the electrons and the holes, a photovoltaic effect is generated
Data Source
AI summary
A method for forming doped regions in a solar cell includes preparing a first and second surface of a substrate, forming a first doped region doped with a first dopant in a part of the first surface, forming a silicon oxide layer on the first surface, the silicon oxide layer including a first silicon oxide layer on the first doped region and having a first thickness, and a second silicon oxide layer on a portion of the first surface not doped by the first dopant and having a second thickness that is less than the first thickness, implanting a second dopant from outside the first surface into the first silicon oxide layer and the second silicon oxide layer, and forming a second doped region adjacent the first doped region by performing heat treatment on the first silicon oxide layer, the second silicon oxide layer, and the substrate.