Suppression of Phase Separation in AlGaInAs Compositionally Graded Buffers for 1550 nm Photovoltaic Converters on GaAs

Fuente: arXiv
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Main Authors: Schulte, Kevin L., Geisz, John F., Guthrey, Harvey L., France, Ryan M., da Costa, Edgard Winter, Steiner, Myles A.
Format: Preprint
Published: 2024
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author Schulte, Kevin L.
Geisz, John F.
Guthrey, Harvey L.
France, Ryan M.
da Costa, Edgard Winter
Steiner, Myles A.
author_facet Schulte, Kevin L.
Geisz, John F.
Guthrey, Harvey L.
France, Ryan M.
da Costa, Edgard Winter
Steiner, Myles A.
contents We investigate strategies to suppress phase separation and reduce threading dislocation densities (TDD) in AlGaInAs compositionally graded buffers (CGBs) that span the lattice constant range from GaAs to InP. Combining results from high resolution x-ray diffraction, cathodoluminescence, transmission electron microscopy, and photovoltaic device measurements, we correlate choices of epitaxial growth conditions with the defect structure of the CGBs and subsequent device performance. Both the use of substrates with high misorientation off (100) towards the (111)A plane and Zn-doping instead of Si-doping are shown to suppress phase separation and reduce TDD. We demonstrate a 0.74 eV GaInAs device grown on a (411)A GaAs substrate using a Zn-doped AlGaInAs CGB with TDD = 3.5 +/- 0.2 x 106 cm^-2 that has a bandgap-open circuit voltage offset of only 0.434 V measured under the AM1.5G solar spectrum. We characterized this device under high-intensity irradiance from a 1570 nm laser and measured a 31.9% peak efficiency laser power conversion efficiency at 3.6 W/cm2. These results provide a roadmap to the manufacture of laser- and thermal-power conversion devices with the performance and cost-effectiveness needed to drive adoption of these technologies at scale.
format Preprint
id arxiv_https___arxiv_org_abs_2411_03218
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Suppression of Phase Separation in AlGaInAs Compositionally Graded Buffers for 1550 nm Photovoltaic Converters on GaAs
Schulte, Kevin L.
Geisz, John F.
Guthrey, Harvey L.
France, Ryan M.
da Costa, Edgard Winter
Steiner, Myles A.
Applied Physics
Materials Science
We investigate strategies to suppress phase separation and reduce threading dislocation densities (TDD) in AlGaInAs compositionally graded buffers (CGBs) that span the lattice constant range from GaAs to InP. Combining results from high resolution x-ray diffraction, cathodoluminescence, transmission electron microscopy, and photovoltaic device measurements, we correlate choices of epitaxial growth conditions with the defect structure of the CGBs and subsequent device performance. Both the use of substrates with high misorientation off (100) towards the (111)A plane and Zn-doping instead of Si-doping are shown to suppress phase separation and reduce TDD. We demonstrate a 0.74 eV GaInAs device grown on a (411)A GaAs substrate using a Zn-doped AlGaInAs CGB with TDD = 3.5 +/- 0.2 x 106 cm^-2 that has a bandgap-open circuit voltage offset of only 0.434 V measured under the AM1.5G solar spectrum. We characterized this device under high-intensity irradiance from a 1570 nm laser and measured a 31.9% peak efficiency laser power conversion efficiency at 3.6 W/cm2. These results provide a roadmap to the manufacture of laser- and thermal-power conversion devices with the performance and cost-effectiveness needed to drive adoption of these technologies at scale.
title Suppression of Phase Separation in AlGaInAs Compositionally Graded Buffers for 1550 nm Photovoltaic Converters on GaAs
topic Applied Physics
Materials Science
url https://arxiv.org/abs/2411.03218