Solar Cell Laser Doping for Substrate Integrity
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Solution Overview
Problem
Current solar cell manufacturing methods face inefficiencies due to high temperature thermal processes that can deteriorate the substrate and require complex high-temperature diffusion processes for impurity distribution, leading to increased costs and potential substrate damage.
Innovation Solution
A method involving the use of laser beam irradiation to locally form back surface field regions by diffusing impurities into the semiconductor substrate, reducing the need for high-temperature thermal processes and improving manufacturing efficiency by selectively doping impurities, thereby forming a p-n junction and enhancing charge distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If high-temperature thermal processes are used for impurity diffusion, then impurity distribution is achieved, but substrate deterioration occurs and manufacturing complexity increases
Solution Approach 1:
The patent replaces the conventional thermal field (heat-based diffusion) with a laser field (optical-based localized heating). The laser beam provides highly localized energy delivery that achieves impurity diffusion only in specific regions without subjecting the entire substrate to high temperatures, thereby avoiding substrate deterioration while maintaining precise impurity distribution control
Solution Approach 2:
The patent implements local quality by applying laser irradiation to specific regions of the semiconductor substrate rather than uniform thermal processing. This creates localized back surface field regions with controlled impurity distribution exactly where needed, preventing unnecessary thermal exposure to other areas and avoiding substrate damage
2Manufacturing precision
If high-temperature thermal processes are used for impurity diffusion, then impurity distribution is achieved, but manufacturing cost and process complexity increase
Solution Approach 1:
The patent replaces complex high-temperature thermal diffusion equipment and processes with a laser processing system. The laser apparatus provides precise control over diffusion depth and location through parameters like power, pulse duration, and scanning speed, simplifying the manufacturing process while achieving superior impurity distribution control
Solution Approach 2:
The patent changes the fundamental processing parameter from temperature (thermal process) to laser power and pulse characteristics (optical process). This parameter transformation enables precise control of impurity diffusion through laser irradiation conditions rather than requiring complex thermal field management, reducing manufacturing complexity
3Quantity of substance
If conventional thermal diffusion is used, then impurities are distributed throughout the substrate, but recombination losses increase and efficiency decreases
Solution Approach 1:
The patent applies local quality by concentrating impurity diffusion only in the back surface region where the laser beam is applied, rather than distributing impurities throughout the entire substrate. This localized approach creates back surface field regions that collect minority carriers without introducing excessive impurities that would cause recombination losses in other regions
Solution Approach 2:
The patent segments the substrate processing into distinct regions: the laser-irradiated back surface region with high impurity concentration for carrier collection, and the bulk substrate region with lower impurity concentration to minimize recombination. This spatial segmentation optimizes both impurity distribution and energy efficiency
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 enhances solar cell efficiency by reducing recombination losses, improving charge collection, and lowering manufacturing costs by eliminating the need for high-temperature processing, while maintaining substrate integrity.
Implementation Method 1
locally forming a back surface field region at the semiconductor substrate by irradiating laser beams onto the semiconductor substrate to diffuse the impurities of the first conductive type into the semiconductor substrate
Implementation Method 2
irradiating laser beams onto the semiconductor substrate to diffuse the impurities of the first conductive type into the semiconductor substrate
Implementation Method 3
When light is incident on the solar cell, a plurality of electron-hole pairs are generated in the semiconductors. The electron-hole pairs are separated into electrons and holes by the photovoltaic effect.
Data Source
AI summary
A method for manufacturing a solar cell may include forming an emitter region that forms a p-n junction with a semiconductor substrate of a first conductive type, forming a passivation layer on the semiconductor substrate, forming a dopant layer containing impurities of the first conductive type on the passivation layer, and locally forming a back surface field region at the semiconductor substrate by irradiating laser beams onto the semiconductor substrate to diffuse the impurities into the semiconductor substrate.