Solar Cell Emitter Pyramid Structure for Lower Contact Resistance
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Solution Overview
Problem
Existing solar cells have poor photoelectric conversion performance due to high contact resistance between the metal electrode and the emitter, which is exacerbated by increased doping concentration leading to recombination centers.
Innovation Solution
A solar cell design featuring a P-type emitter with a first portion having a concave or convex pyramid structure and a second portion with planar inclined surfaces, reducing sheet resistance without increasing doping concentration, thereby improving passivation and ohmic contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If doping concentration is increased to reduce contact resistance, then electrical conductivity improves, but recombination centers increase leading to poor passivation
Solution Approach 1:
The emitter is divided into two regions with different doping concentrations: a first region with higher doping concentration (1E19 to 1E21 atoms/cm³) to reduce contact resistance, and a second region with lower doping concentration (1E17 to 1E19 atoms/cm³) to reduce recombination centers. This local differentiation allows simultaneous optimization of electrical conductivity and passivation quality.
Solution Approach 2:
The emitter is segmented into multiple regions with different properties. The first region (with higher doping) and second region (with lower doping) are spatially separated, allowing each region to fulfill its specific function without interfering with the other, thus resolving the contradiction between conductivity and passivation.
2Reliability
If emitter doping is increased to improve electrical connection with metal electrode, then sheet resistance decreases, but photoelectric conversion performance deteriorates
Solution Approach 1:
Different regions of the emitter have different doping concentrations optimized for their specific functions. The first region has higher doping for low sheet resistance and good electrical connection, while the second region has lower doping for high photoelectric conversion efficiency, achieving both goals simultaneously.
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 design enhances photoelectric conversion efficiency by reducing sheet resistance and maintaining good passivation performance, leading to improved open-circuit voltage and short-circuit current.
Implementation Method 1
a crystal structure of the first portion of the P-type emitter has dislocations
Implementation Method 2
Solar cells have good photoelectric conversion capabilities
Data Source
AI summary
Embodiments of the present disclosure relates to the field of solar cells, and in particular to a solar cell and a production method thereof, and a photovoltaic module. The solar cell includes: a N-type substrate; a P-type emitter formed on a first surface of the N-type substrate and including a first portion and a second portion, a top surface of the first portion includes a first pyramid structure, and at least a part of at least one inclined surface of the first pyramid structure is concave or convex relative to a center of the first pyramid structure, a top surface of the second portion includes a second pyramid structure, and inclined surfaces of the second pyramid structure are planar; and a tunnel layer and a doped conductive layer located on a second surface of the N-type substrate. The present disclosure can improve the photoelectric conversion performance of solar cells.