Effect of Series Resistances on Conversion Efficiency of GaAs/Si Tandem Solar Cells With Areal Current-Matching Technique

Baba, Masaaki; Makita, Kikuo; Mizuno, Hidenori; Takato, Hidetaka; Sugaya, Takeyoshi; Yamada, Noboru

doi:10.1109/jphotov.2018.2790700

Cited by 11 publications

(8 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Regarding the methods to construct III–V-on-Si architectures, a variety of studies have been reported. One of the most straightforward approaches would be the heteroepitaxial growth of GaAs-relevant materials on c-Si substrates; , however, despite the progress of elaborative buffer layer techniques to compensate for the difference in lattice constants and thermal expansion coefficients between GaAs and Si, the layer quality achieved with this type of approach remains a challenge. ,− Alternatively, bonding-based approaches have gained increasing attention, − and as previously mentioned, impressive results have already been obtained by mechanically stacked four-terminal tandems and surface-activation-bonded two-terminal tandems. , We have also developed a unique semiconductor bonding strategy, termed smart stack. − Using well-organized Pd nanoparticle (NP) arrays as bonding mediators, series-connected two-terminal tandem cells consisting of III–V and c-Si subcells have been successfully fabricated with the best efficiency of 30.8% . To make the smart stack technique more attractive, however, it would be preferable to find alternative materials for costly Pd, whose price has recently been rising due to the increasing demand of many other industrial applications…”

Section: Introductionmentioning

confidence: 99%

Cu Nanoparticle Array-Mediated III–V/Si Integration: Application in Series-Connected Tandem Solar Cells

Mizuno

Makita

Mochizuki

et al. 2020

ACS Appl. Energy Mater.

Self Cite

View full text Add to dashboard Cite

The integration of III−V materials with crystalline Si (c-Si) is a promising pathway to design high-performance optoelectronic devices, including solar cells. We have previously reported high-efficiency III−V/Si tandem cells using our unique semiconductor bonding technique, termed smart stack. In the conventional smart stack cells, Pd nanoparticle (NP) arrays have been commonly employed as bonding mediators between III−V and c-Si; however, from an economical point of view, the use of other low-cost metals would be preferable. Therefore, this study focused on the possibility of Cu. A polystyrene-block-poly-2-vinylpyridine (PS-b-P2VP)-based block copolymer was utilized to prepare Cu NP arrays. Desired Cu NP arrays were achieved by starting with self-assembled PS-b-P2VP micelles preloaded with Cu 2+ ions. Satisfying bonding properties (low-resistance interfaces) were confirmed when GaAs subcells were stacked on the Cu NP arrays formed on native-oxide-removed c-Si subcells. Conversion efficiencies of up to 25.9% have been demonstrated with triple-junction structures consisting of InGaP/GaAs top and c-Si bottom subcells. The long-term reliability of Cu NP array-mediated smart stack cells was also verified by the thermal cycle and damp heat tests. Hence, we have successfully confirmed that not only Pd but also Cu is available to realize high-efficiency smart stack cells.

show abstract

Section: Introductionmentioning

confidence: 99%

Cu Nanoparticle Array-Mediated III–V/Si Integration: Application in Series-Connected Tandem Solar Cells

Mizuno

Makita

Mochizuki

et al. 2020

ACS Appl. Energy Mater.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Thus, the photocurrent of the CIGSe bottom cell improved in the previous structures. Furthermore, the ACM technique 57,58 was adapted to reduce the current mismatching degree in a tandem structure. Thus, in this study, the photocurrent of the CIGSe bottom cell was observed to be slightly smaller than that of the InGaP/GaAs upper cell.…”

Section: Device Designmentioning

confidence: 99%

“…Nevertheless, the two-terminal configuration has the advantages of an essentially low optical loss and a simple fabrication process, but the performance is easily affected by current mismatching. In this case, the ACM technique 57,58 is useful for obtaining pseudo-current matching by changing the area of each cell, maintaining a two-terminal configuration. Designing an appropriate area ratio between the two cells would maximize the efficiency.…”

Section: Analysis Of Acm Techniquementioning

confidence: 99%

Mechanical stacked GaAs//CuIn_1−yGa_ySe₂ three‐junction solar cells with 30% efficiency via an improved bonding interface and area current‐matching technique

Makita

Kamikawa

Koida

et al. 2022

Progress in Photovoltaics

Self Cite

View full text Add to dashboard Cite

Multijunction (MJ) solar cells have attracted considerable attention as nextgeneration solar cells. III-V-based MJ solar cells connected to heterogeneous cells, such as GaAs//Si and GaAs//CIGSe (CuIn 1Ày Ga y Se 2 ), are expected to be highly efficient and inexpensive. Consequently, we have developed a mechanical stacking method with Pd nanoparticles and silicone adhesives for the bonding interface, which was modified for our previous "smart stack" technology. Using this "modified smart stack," we previously demonstrated an InGaP/Al 0.06 Ga 0.94 As//CIGSe three-junction solar cell with an efficiency of 28.06%. In this study, we fabricated an InGaP/GaAs// CIGSe three-junction solar cell. The total efficiency is 29.3% for the aperture area (31.0% for the active area) under AM1.5G solar spectrum illumination, which is the optimal value reported for two-terminal GaAs//CIGSe-based tandem solar cells thus far. This superior performance was realized by using a specialized CIGSe cell with a flattened surface via a wet etching process and a thin In 2 O 3 ;Ce,H transparent conducting oxide layer. Using an area current-matching technique, the efficiency increased to 30%. In addition, the bonding resistivity of the fabricated solar cell was estimated to be less than 1 Ωcm 2 from solar-concentrated measurements. These results suggest the potential of III-V//CIGSe-based tandem solar cells with modified smart stack technology as next-generation photovoltaic cells for applications such as vehicle-integrated photovoltaics. K E Y W O R D S bonding technology, CuIn 1Ày Ga y Se 2 solar cells, III-V solar cells, mechanical stack, multijunction solar cells 1 | INTRODUCTION Multijunction (MJ) solar cells have very high efficiencies (>30%) owing to their effective utilization of solar energy. MJ solar cells fabricated using mechanical stacking technology 1-8 have been recognized as next-generation solar cells. The mechanical stacking technology is flexible, which allows for the most appropriate combination of different cells to be selected, enabling the construction of efficient and low-cost solar cells. Currently, the most promising combination is that of a III-V-based MJ solar cell connected to a heterogeneous solar cell, such as GaAs//Si or GaAs//CuIn 1Ày Ga y Se 2 (hereafter referred to as CIGSe). GaAs-based cells are highly efficient and reliable. Si and CIGSe

show abstract

“…Since upper cell materials with suitable bandgap are of critical importance for multi-junction TSCs, numerous semiconductors have been deeply studied, including III-V and II-VI compounds, organic/inorganic perovskite materials, etc. [7][8][9].…”

Section: Introductionmentioning

confidence: 99%

Size-Dependent and Enhanced Photovoltaic Performance of Solar Cells Based on Si Quantum Dots

Cao

Zhu

et al. 2020

Energies

View full text Add to dashboard Cite

Recently, extensive studies have focused on exploring a variety of silicon (Si) nanostructures among which Si quantum dots (Si QDs) may be applied in all Si tandem solar cells (TSCs) for the time to come. By virtue of its size tunability, the optical bandgap of Si QDs is capable of matching solar spectra in a broad range and thus improving spectral response. In the present work, size-controllable Si QDs are successfully obtained through the formation of Si QDs/SiC multilayers (MLs). According to the optical absorption measurement, the bandgap of Si QDs/SiC MLs shows a red shift to the region of long wavelength when the size of dots increases, well conforming to quantum confinement effect (QCE). Additionally, heterojunction solar cells (HSCs) based on Si QDs/SiC MLs of various sizes are presented and studied, which demonstrates the strong dependence of photovoltaic performance on the size of Si QDs. The measurement of external quantum efficiency (EQE) reveals the contribution of Si QDs to the response and absorption in the ultraviolet–visible (UV-Vis) light range. Furthermore, Si QDs/SiC MLs-based solar cell shows the best power conversion efficiency (PCE) of 10.15% by using nano-patterned Si light trapping substrates.

show abstract

Effect of Series Resistances on Conversion Efficiency of GaAs/Si Tandem Solar Cells With Areal Current-Matching Technique

Cited by 11 publications

References 24 publications

Cu Nanoparticle Array-Mediated III–V/Si Integration: Application in Series-Connected Tandem Solar Cells

Cu Nanoparticle Array-Mediated III–V/Si Integration: Application in Series-Connected Tandem Solar Cells

Mechanical stacked GaAs//CuIn_1−yGa_ySe₂ three‐junction solar cells with 30% efficiency via an improved bonding interface and area current‐matching technique

Size-Dependent and Enhanced Photovoltaic Performance of Solar Cells Based on Si Quantum Dots

Contact Info

Product

Resources

About

Effect of Series Resistances on Conversion Efficiency of GaAs/Si Tandem Solar Cells With Areal Current-Matching Technique

Cited by 11 publications

References 24 publications

Cu Nanoparticle Array-Mediated III–V/Si Integration: Application in Series-Connected Tandem Solar Cells

Cu Nanoparticle Array-Mediated III–V/Si Integration: Application in Series-Connected Tandem Solar Cells

Mechanical stacked GaAs//CuIn1−yGaySe2 three‐junction solar cells with 30% efficiency via an improved bonding interface and area current‐matching technique

Size-Dependent and Enhanced Photovoltaic Performance of Solar Cells Based on Si Quantum Dots

Contact Info

Product

Resources

About

Mechanical stacked GaAs//CuIn_1−yGa_ySe₂ three‐junction solar cells with 30% efficiency via an improved bonding interface and area current‐matching technique