K Improves Cu(In,Ga)Se2 Surface Band Alignment through Reconstruction

Christopher P. Muzzillo; Stephen Glynn; Glenn Teeter; Lorelle M. Mansfield

doi:10.1021/acsaem.2c01815

K Improves Cu(In,Ga)Se2 Surface Band Alignment through Reconstruction

Christopher P. Muzzillo, Stephen Glynn, Glenn Teeter, Lorelle M. Mansfield

Materials Science

Research output: Contribution to journal › Article › peer-review

2 Scopus Citations

Abstract

K, Rb, and Cs improve Cu(In,Ga)Se₂(CIGS) solar cell performance, but the mechanism remains unclear. Here we use air-free transfer of multiple samples to study KF post-deposition treatments (PDTs) by X-ray photoelectron spectroscopy. The KF PDTs do not change the majority carrier concentration or Cd in-diffusion, but they boost efficiency by 6.1% absolute, improve minority carrier lifetime, and shift the surface valence band further from the Fermi energy. Unlike former reports, the valence-band shift is not a result of lower Cu/(Ga+In) or higher K/(K+Cu) composition ratios. We propose that instead, KF PDTs alter the surface valence-band alignment through a reconstructive phase transformation from chalcopyrite CIGS to K₂CuIn₃Se₆or KInSe₂, which have layered structures.

Original language	American English
Pages (from-to)	11328-11338
Number of pages	11
Journal	ACS Applied Energy Materials
Volume	5
Issue number	9
DOIs	https://doi.org/10.1021/acsaem.2c01815 https://doi.org/10.1021/acsaem.2c01815
State	Published - 26 Sep 2022

Bibliographical note

Publisher Copyright:
© 2022 American Chemical Society. All rights reserved.

NREL Publication Number

NREL/JA-5K00-83188

Keywords

chalcopyrite
CIGS
photovoltaics
potassium
reconstruction

Access to Document

https://www.nrel.gov/docs/fy22osti/83188.pdf

Cite this

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title = "K Improves Cu(In,Ga)Se2 Surface Band Alignment through Reconstruction",

abstract = "K, Rb, and Cs improve Cu(In,Ga)Se2(CIGS) solar cell performance, but the mechanism remains unclear. Here we use air-free transfer of multiple samples to study KF post-deposition treatments (PDTs) by X-ray photoelectron spectroscopy. The KF PDTs do not change the majority carrier concentration or Cd in-diffusion, but they boost efficiency by 6.1% absolute, improve minority carrier lifetime, and shift the surface valence band further from the Fermi energy. Unlike former reports, the valence-band shift is not a result of lower Cu/(Ga+In) or higher K/(K+Cu) composition ratios. We propose that instead, KF PDTs alter the surface valence-band alignment through a reconstructive phase transformation from chalcopyrite CIGS to K2CuIn3Se6or KInSe2, which have layered structures.",

keywords = "chalcopyrite, CIGS, photovoltaics, potassium, reconstruction",

author = "Muzzillo, {Christopher P.} and Stephen Glynn and Glenn Teeter and Mansfield, {Lorelle M.}",

year = "2022",

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doi = "10.1021/acsaem.2c01815",

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TY - JOUR

T1 - K Improves Cu(In,Ga)Se2 Surface Band Alignment through Reconstruction

AU - Muzzillo, Christopher P.

AU - Glynn, Stephen

AU - Teeter, Glenn

AU - Mansfield, Lorelle M.

PY - 2022/9/26

Y1 - 2022/9/26

N2 - K, Rb, and Cs improve Cu(In,Ga)Se2(CIGS) solar cell performance, but the mechanism remains unclear. Here we use air-free transfer of multiple samples to study KF post-deposition treatments (PDTs) by X-ray photoelectron spectroscopy. The KF PDTs do not change the majority carrier concentration or Cd in-diffusion, but they boost efficiency by 6.1% absolute, improve minority carrier lifetime, and shift the surface valence band further from the Fermi energy. Unlike former reports, the valence-band shift is not a result of lower Cu/(Ga+In) or higher K/(K+Cu) composition ratios. We propose that instead, KF PDTs alter the surface valence-band alignment through a reconstructive phase transformation from chalcopyrite CIGS to K2CuIn3Se6or KInSe2, which have layered structures.

AB - K, Rb, and Cs improve Cu(In,Ga)Se2(CIGS) solar cell performance, but the mechanism remains unclear. Here we use air-free transfer of multiple samples to study KF post-deposition treatments (PDTs) by X-ray photoelectron spectroscopy. The KF PDTs do not change the majority carrier concentration or Cd in-diffusion, but they boost efficiency by 6.1% absolute, improve minority carrier lifetime, and shift the surface valence band further from the Fermi energy. Unlike former reports, the valence-band shift is not a result of lower Cu/(Ga+In) or higher K/(K+Cu) composition ratios. We propose that instead, KF PDTs alter the surface valence-band alignment through a reconstructive phase transformation from chalcopyrite CIGS to K2CuIn3Se6or KInSe2, which have layered structures.

KW - chalcopyrite

KW - CIGS

KW - photovoltaics

KW - potassium

KW - reconstruction

UR - http://www.scopus.com/inward/record.url?scp=85137299923&partnerID=8YFLogxK

U2 - 10.1021/acsaem.2c01815

DO - 10.1021/acsaem.2c01815

M3 - Article

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SN - 2574-0962

VL - 5

SP - 11328

EP - 11338

JO - ACS Applied Energy Materials

JF - ACS Applied Energy Materials

IS - 9

ER -

K Improves Cu(In,Ga)Se2 Surface Band Alignment through Reconstruction

Abstract

Bibliographical note

NREL Publication Number

Keywords

Access to Document

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