Tandem Solar Battery Interlayer Structure to Limit Recombination

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Solution Overview

Problem

Current solar batteries have not yet achieved ideal light utilization efficiency, necessitating a rational design of their structure to enhance cell efficiency.

Innovation Solution

A tandem solar battery design featuring a first and second photoelectric conversion layer with distinct bandgaps, interspersed with a first charge transport layer, a transparent conductive layer, a second charge transport layer, and a polysilicon layer, where the second charge transport layer is positioned between the polysilicon layer and the transparent conductive layer, ensuring consistent charge transport properties and preventing recombination phenomena.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a tandem solar battery structure with multiple charge transport layers and a polysilicon layer is adopted, then photoelectric conversion efficiency is improved, but device complexity increases

Engineering Contradiction:
Improvephotoelectric conversion efficiencyVSAvoidstructure complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The solar battery is divided into multiple functional segments including first and second photoelectric conversion layers with different bandgaps, charge transport layers, a transparent conductive layer, and a polysilicon layer. Each segment performs a specific function in the photoelectric conversion process, allowing optimization of light absorption and charge transport across different spectral ranges.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements a nested structure where the transparent conductive layer is positioned within the stack between charge transport layers, and the polysilicon layer is integrated into the sequence. This nested arrangement allows multiple functional layers to be compactly organized while maintaining their individual roles in charge transport and light management.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Productivity

If the second charge transport layer is positioned between the polysilicon layer and the transparent conductive layer, then charge transport efficiency is improved and recombination is reduced, but manufacturing precision requirements increase

Engineering Contradiction:
Improvecharge transport efficiencyVSAvoidlayer positioning precision
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The second charge transport layer is specifically positioned at the interface between the polysilicon layer and transparent conductive layer, where charge transport conditions differ from other regions. This localized placement optimizes charge extraction at this critical interface while maintaining appropriate thickness and material properties specific to this position.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The second charge transport layer acts as an intermediary between the polysilicon layer and transparent conductive layer, facilitating charge transfer between these two materials with different electrical properties. This intermediate layer prevents direct contact that could cause recombination, while still enabling efficient charge transport through its mediating function.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If multiple layers with consistent charge transport properties are used, then recombination phenomena are avoided, but manufacturing cost increases

Engineering Contradiction:
Improverecombination preventionVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The charge transport layers are designed with consistent charge transport properties throughout the device, using materials with matched mobility and energy level characteristics. This homogeneity in transport properties across different layers ensures uniform charge flow and prevents accumulation or recombination at interfaces between layers with mismatched properties.

Inventive Principle:
Principle #33Homogeneity

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 configuration effectively improves the solar battery's efficiency, maintains a simple structure and low manufacturing costs, and enhances charge transport, leading to increased photoelectric conversion efficiency.

Implementation Method 1

a first cell comprising a first photoelectric conversion layer comprising a first photoelectric conversion material having a first bandgap, a second cell comprising a second photoelectric conversion layer comprising a second photoelectric conversion material having a second bandgap

Methodology Applied
Scientific EffectPhotovoltaic effect: Photovoltaic Effect

Data Source

PatentEP4325586A1A solar battery
Publication Date: 2024.02.21 TRINA SOLAR CO LTD
  • EP4325586A1 patent drawingFigure 1
  • EP4325586A1 patent drawingFigure 2
  • EP4325586A1 patent drawing

AI summary

The present disclosure relates to a solar battery including a first cell, and a second cell, and a first charge transport layer, a transparent conductive layer, a second charge transport layer and a polysilicon layer are disposed between the first photoelectric conversion layer of the first cell and the second photoelectric conversion layer of the second cell, and the second charge transport layer is disposed between the polysilicon layer and the transparent conductive layer, and the charge transport property of the second charge transport layer is the same as that of the polysilicon layer. In the solar battery of the present disclosure, a first charge transport layer, a transparent conductive layer, a second charge transport layer and a polysilicon layer are sequentially arranged between the first photoelectric conversion layer and the second photoelectric conversion layer. Especially the second charge transport layer may protect the polysilicon layer, may effectively transport the same type of charges, and avoid recombination phenomena at the interface or inside the film, thereby effectively improving the efficiency of the battery. The solar battery of this disclosure also has the characteristics of simple structure, simple and convenient manufacturing process, and low cost.