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Composition, Optical Resonances, and Doping of InP/InGaP Nanowires for Tandem Solar Cells : a Micro-Raman Analysis

Mediavilla, Irene ; Pura, Jose Luis ; Hinojosa, Vanessa Giselle ; Galiana, Beatriz ; Hrachowina, Lukas LU ; Borgström, Magnus T. LU and Jimenez, Juan (2023) In ACS Nano
Abstract

We present a micro-Raman study of InP/InGaP tandem junction photovoltaic nanowires. These nanowires render possible InGaP compositions that cannot be made in thin films due to strain. The micro-Raman spectra acquired along the nanowires reveal the existence of compositional changes in the InGaP alloy associated with the doping sequence. The heavily Zn-doped InxGa1-xP (x is the In molar fraction) side of the tunnel diode is Ga rich, x = 0.25, with respect to the n-type and intrinsic segments of the top cell, which are close to the nominal composition of the NWs (x = 0.35). The p-type end segment is still Ga-rich. Electromagnetic resonances are observed in the tunnel diode. The Raman signal arising from the InGaP... (More)

We present a micro-Raman study of InP/InGaP tandem junction photovoltaic nanowires. These nanowires render possible InGaP compositions that cannot be made in thin films due to strain. The micro-Raman spectra acquired along the nanowires reveal the existence of compositional changes in the InGaP alloy associated with the doping sequence. The heavily Zn-doped InxGa1-xP (x is the In molar fraction) side of the tunnel diode is Ga rich, x = 0.25, with respect to the n-type and intrinsic segments of the top cell, which are close to the nominal composition of the NWs (x = 0.35). The p-type end segment is still Ga-rich. Electromagnetic resonances are observed in the tunnel diode. The Raman signal arising from the InGaP side of the tunnel diode is significantly enhanced. This enhancement permits the observation of a Raman mode that can be associated with an LO phonon plasmon coupled mode (LOPCM). This mode has not been previously reported in the literature of InGaP, and it permits the Raman characterization of the tunnel diode. The analysis of this mode and its relation to the LO phonon modes of the alloy, InP-like and GaP-like, allows to establish an apparent one-mode behavior for the phonon plasmon coupling. It indicates that hole plasma couples to the GaP-like LO mode. The LOPCMs are modeled using the Lindhard Mermin formalism for the dielectric function.

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author
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organization
publishing date
type
Contribution to journal
publication status
epub
subject
keywords
alloy composition, InGaP, InP axial heterostructures, plasmon modes, Raman, semiconductor nanowires, tunnel diode
in
ACS Nano
publisher
The American Chemical Society (ACS)
external identifiers
  • pmid:38536891
  • scopus:85189009095
ISSN
1936-0851
DOI
10.1021/acsnano.3c12973
language
English
LU publication?
yes
id
20f2c377-641d-451e-bc6d-aafac56268dc
date added to LUP
2024-04-11 12:15:14
date last changed
2024-05-09 16:39:38
@article{20f2c377-641d-451e-bc6d-aafac56268dc,
  abstract     = {{<p>We present a micro-Raman study of InP/InGaP tandem junction photovoltaic nanowires. These nanowires render possible InGaP compositions that cannot be made in thin films due to strain. The micro-Raman spectra acquired along the nanowires reveal the existence of compositional changes in the InGaP alloy associated with the doping sequence. The heavily Zn-doped In<sub>x</sub>Ga<sub>1-x</sub>P (x is the In molar fraction) side of the tunnel diode is Ga rich, x = 0.25, with respect to the n-type and intrinsic segments of the top cell, which are close to the nominal composition of the NWs (x = 0.35). The p-type end segment is still Ga-rich. Electromagnetic resonances are observed in the tunnel diode. The Raman signal arising from the InGaP side of the tunnel diode is significantly enhanced. This enhancement permits the observation of a Raman mode that can be associated with an LO phonon plasmon coupled mode (LOPCM). This mode has not been previously reported in the literature of InGaP, and it permits the Raman characterization of the tunnel diode. The analysis of this mode and its relation to the LO phonon modes of the alloy, InP-like and GaP-like, allows to establish an apparent one-mode behavior for the phonon plasmon coupling. It indicates that hole plasma couples to the GaP-like LO mode. The LOPCMs are modeled using the Lindhard Mermin formalism for the dielectric function.</p>}},
  author       = {{Mediavilla, Irene and Pura, Jose Luis and Hinojosa, Vanessa Giselle and Galiana, Beatriz and Hrachowina, Lukas and Borgström, Magnus T. and Jimenez, Juan}},
  issn         = {{1936-0851}},
  keywords     = {{alloy composition; InGaP; InP axial heterostructures; plasmon modes; Raman; semiconductor nanowires; tunnel diode}},
  language     = {{eng}},
  publisher    = {{The American Chemical Society (ACS)}},
  series       = {{ACS Nano}},
  title        = {{Composition, Optical Resonances, and Doping of InP/InGaP Nanowires for Tandem Solar Cells : a Micro-Raman Analysis}},
  url          = {{http://dx.doi.org/10.1021/acsnano.3c12973}},
  doi          = {{10.1021/acsnano.3c12973}},
  year         = {{2023}},
}