High‐Efficiency Flexible GaAs/InGaAs Dual‐Junction Solar Cells Fabricated by Metallic Nanoparticle‐Based Wafer Bonding

Multijunction solar cells made from highly lattice‐mismatched (LMM) material systems offer an optimal bandgap combination for the ultrahigh conversion of solar energy to electricity. Conventional fabrication techniques for multijunction cells, such as metamorphic epitaxy, direct wafer bonding, and a...

Full description

Saved in:
Bibliographic Details
Main Authors: Yeongho Kim, Suho Park, Thuy Thi Nguyen, Jiyeon Jeon, Byong Sun Chun, Sang Jun Lee
Format: Article
Language:English
Published: Wiley-VCH 2025-02-01
Series:Small Structures
Subjects:
Online Access:https://doi.org/10.1002/sstr.202400421
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1832542202450935808
author Yeongho Kim
Suho Park
Thuy Thi Nguyen
Jiyeon Jeon
Byong Sun Chun
Sang Jun Lee
author_facet Yeongho Kim
Suho Park
Thuy Thi Nguyen
Jiyeon Jeon
Byong Sun Chun
Sang Jun Lee
author_sort Yeongho Kim
collection DOAJ
description Multijunction solar cells made from highly lattice‐mismatched (LMM) material systems offer an optimal bandgap combination for the ultrahigh conversion of solar energy to electricity. Conventional fabrication techniques for multijunction cells, such as metamorphic epitaxy, direct wafer bonding, and adhesive wafer bonding, are still expensive and produce low yields owing to the use of complex process steps and sophisticated equipment. Herein, flexible GaAs/In0.53Ga0.47As dual‐junction solar cells with a large lattice mismatch of 3.7% between the subcells are fabricated using an indium‐tin‐oxide (ITO) nanoparticle‐based wafer bonding process. The ITO bonding layer electrically and optically connecting the GaAs top and InGaAs bottom cells shows a low series resistance of 5.7 × 10−2 Ω cm−2 and a high optical transmission of 90% in the infrared range of 870–1800 nm. The dark current characteristic of the ITO‐bonded dual‐junction cell exhibits a good rectifying behavior with a high on–off ratio of ≈105 at ±2 V. Under 1 sun AM 1.5G illumination, a high power conversion efficiency of 28.5% is achieved for the two‐terminal series‐connected dual‐junction cell, with an average external radiative efficiency of 2.6%. In these findings, it is suggested that ITO nanoparticle‐based wafer bonding may be a facile and cost‐effective route for fabricating LMM solar cells, potentially overcoming the Shockley–Queisser efficiency limit.
format Article
id doaj-art-d8e4f0062f52417588e7db3edb6677ac
institution Kabale University
issn 2688-4062
language English
publishDate 2025-02-01
publisher Wiley-VCH
record_format Article
series Small Structures
spelling doaj-art-d8e4f0062f52417588e7db3edb6677ac2025-02-04T08:10:21ZengWiley-VCHSmall Structures2688-40622025-02-0162n/an/a10.1002/sstr.202400421High‐Efficiency Flexible GaAs/InGaAs Dual‐Junction Solar Cells Fabricated by Metallic Nanoparticle‐Based Wafer BondingYeongho Kim0Suho Park1Thuy Thi Nguyen2Jiyeon Jeon3Byong Sun Chun4Sang Jun Lee5School of Materials Science and Engineering Chonnam National University Gwangju 61186 Republic of KoreaStrategic Technology Research Institute Korea Research Institute of Standards and Science Daejeon 34113 Republic of KoreaStrategic Technology Research Institute Korea Research Institute of Standards and Science Daejeon 34113 Republic of KoreaStrategic Technology Research Institute Korea Research Institute of Standards and Science Daejeon 34113 Republic of KoreaStrategic Technology Research Institute Korea Research Institute of Standards and Science Daejeon 34113 Republic of KoreaStrategic Technology Research Institute Korea Research Institute of Standards and Science Daejeon 34113 Republic of KoreaMultijunction solar cells made from highly lattice‐mismatched (LMM) material systems offer an optimal bandgap combination for the ultrahigh conversion of solar energy to electricity. Conventional fabrication techniques for multijunction cells, such as metamorphic epitaxy, direct wafer bonding, and adhesive wafer bonding, are still expensive and produce low yields owing to the use of complex process steps and sophisticated equipment. Herein, flexible GaAs/In0.53Ga0.47As dual‐junction solar cells with a large lattice mismatch of 3.7% between the subcells are fabricated using an indium‐tin‐oxide (ITO) nanoparticle‐based wafer bonding process. The ITO bonding layer electrically and optically connecting the GaAs top and InGaAs bottom cells shows a low series resistance of 5.7 × 10−2 Ω cm−2 and a high optical transmission of 90% in the infrared range of 870–1800 nm. The dark current characteristic of the ITO‐bonded dual‐junction cell exhibits a good rectifying behavior with a high on–off ratio of ≈105 at ±2 V. Under 1 sun AM 1.5G illumination, a high power conversion efficiency of 28.5% is achieved for the two‐terminal series‐connected dual‐junction cell, with an average external radiative efficiency of 2.6%. In these findings, it is suggested that ITO nanoparticle‐based wafer bonding may be a facile and cost‐effective route for fabricating LMM solar cells, potentially overcoming the Shockley–Queisser efficiency limit.https://doi.org/10.1002/sstr.202400421indium tin oxideslattice mismatchesmultijunction solar cellsnanoparticleswafer bondings
spellingShingle Yeongho Kim
Suho Park
Thuy Thi Nguyen
Jiyeon Jeon
Byong Sun Chun
Sang Jun Lee
High‐Efficiency Flexible GaAs/InGaAs Dual‐Junction Solar Cells Fabricated by Metallic Nanoparticle‐Based Wafer Bonding
Small Structures
indium tin oxides
lattice mismatches
multijunction solar cells
nanoparticles
wafer bondings
title High‐Efficiency Flexible GaAs/InGaAs Dual‐Junction Solar Cells Fabricated by Metallic Nanoparticle‐Based Wafer Bonding
title_full High‐Efficiency Flexible GaAs/InGaAs Dual‐Junction Solar Cells Fabricated by Metallic Nanoparticle‐Based Wafer Bonding
title_fullStr High‐Efficiency Flexible GaAs/InGaAs Dual‐Junction Solar Cells Fabricated by Metallic Nanoparticle‐Based Wafer Bonding
title_full_unstemmed High‐Efficiency Flexible GaAs/InGaAs Dual‐Junction Solar Cells Fabricated by Metallic Nanoparticle‐Based Wafer Bonding
title_short High‐Efficiency Flexible GaAs/InGaAs Dual‐Junction Solar Cells Fabricated by Metallic Nanoparticle‐Based Wafer Bonding
title_sort high efficiency flexible gaas ingaas dual junction solar cells fabricated by metallic nanoparticle based wafer bonding
topic indium tin oxides
lattice mismatches
multijunction solar cells
nanoparticles
wafer bondings
url https://doi.org/10.1002/sstr.202400421
work_keys_str_mv AT yeonghokim highefficiencyflexiblegaasingaasdualjunctionsolarcellsfabricatedbymetallicnanoparticlebasedwaferbonding
AT suhopark highefficiencyflexiblegaasingaasdualjunctionsolarcellsfabricatedbymetallicnanoparticlebasedwaferbonding
AT thuythinguyen highefficiencyflexiblegaasingaasdualjunctionsolarcellsfabricatedbymetallicnanoparticlebasedwaferbonding
AT jiyeonjeon highefficiencyflexiblegaasingaasdualjunctionsolarcellsfabricatedbymetallicnanoparticlebasedwaferbonding
AT byongsunchun highefficiencyflexiblegaasingaasdualjunctionsolarcellsfabricatedbymetallicnanoparticlebasedwaferbonding
AT sangjunlee highefficiencyflexiblegaasingaasdualjunctionsolarcellsfabricatedbymetallicnanoparticlebasedwaferbonding