Inverted Metamorphic Multijunction Solar Cell Single Layer

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Solution Overview

Problem

Existing methods for manufacturing inverted metamorphic multijunction solar cells using III-V compound semiconductor materials face challenges in achieving commercially viable and energy-efficient production due to difficulties in material selection and fabrication steps.

Innovation Solution

The development of a multijunction solar cell structure incorporating a graded interlayer of (InxGa1-x)y Al1-yAs and a high band gap contact layer of p++ type InGaAlAs or InGaAs, with a surrogate substrate mounted on top and the original substrate removed, allowing for the growth of subcells with varying band gaps on a single metamorphic layer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If multiple metamorphic layers are used to achieve spectral splitting, then energy conversion efficiency is improved, but device complexity and manufacturing difficulty increase

Engineering Contradiction:

Improveenergy conversion efficiencyVSAvoidmanufacturing complexity

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The patent combines multiple photovoltaic functions into a single metamorphic layer by growing different semiconductor materials (GaInP, GaAs, Ge) with varying band gaps in a stacked configuration within one layer, eliminating the need for multiple separate metamorphic layers while achieving spectral splitting and high energy conversion efficiency

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The single metamorphic layer serves multiple functions: it provides lattice matching for different semiconductor materials, enables spectral splitting through varying band gaps, and acts as a unified growth substrate for multiple subcells, reducing overall device complexity while maintaining high efficiency

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Loss of energy

If III-V compound semiconductor materials are used, then energy conversion efficiency is improved, but ease of manufacture deteriorates

Engineering Contradiction:

Improveenergy conversion efficiencyVSAvoidease of manufacture

Core Design Contradiction:

Loss of energyVSEase of manufacture

Solution Approach 1:

The patent inverts the conventional growth approach by growing subcells in reverse order (from top to bottom: GaInP, then GaAs, then Ge) on a single metamorphic layer, which simplifies the fabrication process and improves manufacturability while maintaining the high efficiency benefits of III-V compounds

Inventive Principle:

Principle #13The other way round (Inversion)

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 enables the production of high-efficiency solar cells with improved radiation resistance and efficiency, exceeding 32% under specific conditions, by optimizing the band gap and lattice constants of the semiconductor layers through controlled growth processes.

Implementation Method 1

a graded interlayer adjacent to the first sequence of layers, the graded interlayer being composed of (InxGa1-x)yAl1-yAs

Methodology Applied

Scientific EffectGraded buffering:

Implementation Method 2

the ability to achieve spectral splitting of the incident radiation through the use of a plurality of photovoltaic regions with different band gap energies, and accumulating the current from each of the regions

Methodology Applied

Scientific EffectPhotovoltaic effect: Photovoltaic Effect

Data Source

PatentUS10170656B2Inverted metamorphic multijunction solar cell with a single metamorphic layer

Publication Date: 2019.01.01 SOLAERO TECHNOLOGIES CORP

AI summary

The present disclosure provides a multijunction solar cell that includes: a first sequence of layers of semiconductor material forming a first set of one or more solar subcells; a graded interlayer adjacent to said first sequence of layers; a second sequence of layers of semiconductor material forming a second set of one or more solar subcells; and a high band gap contact layer adjacent said second sequence of layers, wherein the high band gap contact layer is composed of p++ type InGaAlAs or InGaAs.