Development of Low-TDD GaAsyP1-y/GaP/Si Metamorphic Materials for High-Efficiency III-V/Si Photovoltaics
| Autor: | Jacob T. Boyer, Steven A. Ringel, Ari N. Blumer, Daniel L. Lepkowski, Zak H. Blumer, Tyler J. Grassman, Francisco A. Rodriguez |
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| Rok vydání: | 2020 |
| Předmět: |
010302 applied physics
Materials science Silicon business.industry Photovoltaic system chemistry.chemical_element Heterojunction 02 engineering and technology 021001 nanoscience & nanotechnology Epitaxy 7. Clean energy 01 natural sciences Gallium arsenide chemistry.chemical_compound chemistry Photovoltaics 0103 physical sciences Optoelectronics Metalorganic vapour phase epitaxy Dislocation 0210 nano-technology business |
| Zdroj: | 2020 47th IEEE Photovoltaic Specialists Conference (PVSC). |
| DOI: | 10.1109/pvsc45281.2020.9300803 |
| Popis: | Metamorphic III-V/Si materials with low threading dislocation density (TDD) are critical to realizing high-efficiency III-V/Si multijunction photovoltaics. In pursuit of a dual junction III-V/Si design with a GaAs 0.75 P 0.25 top junction epitaxially integrated on a Si bottom junction, we report on progress made in the development of GaP/Si and GaAsyP l-y /Si materials with significantly reduced TDD. Using a tightly integrated study of fundamental dislocation dynamics, rapid electron microscopy based feedback on dislocation populations, and MOCVD process development, we have fully re-engineered the GaP on Si growth process. Our new approach results in a TDD of 7x104 cm−2 for 50 nm thick films. Implementation of a novel dislocation glide enhancing heterostructure then enabled subsequent growth of fully-relaxed, 500 nm total thickness n-GaP with a TDD of 2.4×106 cm−2. When applied to the production of full GaAs 0.75 P 0.25 /Si tandem solar cell structures, but without any significant optimization thus far, this low TDD is effectively maintained, yielding a terminal TDD of only 3.0x106 cm−2, sufficient to support high photovoltaic performance. |
| Databáze: | OpenAIRE |
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