Solar Cell Eutectic Contact Layer for Low-Resistance Textured Emitters
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional solar cells face poor photoelectric conversion efficiency due to optical and electrical losses, primarily attributed to reflective losses, shadowing, non-absorptive losses, and high contact resistances between metal and semiconductor surfaces.
Innovation Solution
A solar cell design featuring a substrate with a textured emitter structure, passivation layers, and conductive eutectic layers composed of differently shaped conductive particles, which reduce contact resistances and enhance the contact area, thereby improving electrical efficiency and optical absorption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional metal contact structures are used on the emitter surface, then the device complexity is low and manufacturing is simple, but the contact resistance is high and electrical losses increase
Solution Approach 1:
The patent uses a composite conductive eutectic layer comprising multiple types of conductive particles (first conductive particles with branched/linear shapes and second conductive particles with different shapes) embedded in a glass matrix. This composite structure reduces contact resistance between the metal electrode and semiconductor emitter while managing the complexity through a controlled particle ratio (20%-80%) and standardized manufacturing process.
2Reliability
If the contact area between metal and semiconductor is increased, then the contact resistance decreases, but the shadowing losses increase and optical absorption decreases
Solution Approach 1:
The patent applies local quality by using conductive particles with specific branched and linear shapes that concentrate conductivity at contact points while maintaining optical transparency in non-contact areas. The textured structure on the emitter surface further enhances this by creating localized contact zones that minimize shadowing while maximizing electrical contact.
Solution Approach 2:
The conductive particles feature curved branched and linear shapes rather than flat configurations. This curvature allows the particles to conform to the textured emitter surface, increasing contact area through geometric adaptation while the three-dimensional structure minimizes the projected shadow area, thus reducing optical losses.
3Reliability
If conductive particles are placed close to the emitter surface, then the contact resistance decreases, but the corrosion of the textured structure increases
Solution Approach 1:
The glass matrix acts as an intermediary between the conductive particles and the semiconductor emitter. It provides a protective barrier that prevents direct corrosive interaction between the conductive particles and the textured structure, while still allowing electrical contact to occur. The eutectic composition of the glass matrix is specifically designed to reduce corrosion at the interface.
4Reliability
If uniform conductive particles are used in the eutectic layer, then the manufacturing precision is high and process control is simple, but the contact area and electrical conductivity are insufficient
Solution Approach 1:
The patent changes the parameter of particle shape diversity by incorporating both branched and linear shaped first conductive particles along with second conductive particles of different shapes. This parameter change increases the contact area and electrical conductivity. The manufacturing precision is maintained through controlling the ratio of first to second conductive particles within 20%-80% and using standardized screen printing and energy injection processes.
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 significantly reduces electrical losses, increases open-circuit voltage, and enhances photoelectric conversion efficiency by increasing the contact area and distance between conductive particles and the PN junction, while preventing excessive corrosion and maintaining optical performance.
Implementation Method 1
conductive eutectic layers, where each of the conductive eutectic layers is formed between a respective first electrode of the first electrodes and the emitter and includes first conductive particles and second conductive particles
Implementation Method 2
Optical losses include reflective losses on a front surface of the cell
Implementation Method 3
Optical losses include reflective losses on a front surface of the cell
Implementation Method 4
a passivation structure formed on the textured structure of the emitter
Implementation Method 5
solar cells are being used more and more widely as a new energy alternative, which convert light energy from the sun into electrical energy. The solar cells utilize the photovoltaic principle to generate carriers
Data Source
AI summary
A solar cell is provided, including a substrate having a first surface and a second surface opposite to each other, an emitter formed on the first surface of the substrate and including a textured structure on a side away from the first surface, a passivation structure formed on the textured structure, first electrodes penetrating the passivation structure and in electrical contact with the textured structure of the emitter, and conductive eutectic layers each formed between a respective first electrode and the emitter and including first conductive particles and second conductive particles. Each of the first conductive particles has a shape different from a shape of any of the second conductive particles. The first conductive particles and the second conductive particles have a first number, the first conductive particles have a second number, and a ratio of the second number to the first number in a range of 20% to 80%.