KF post-deposition treatment of industrial Cu(In, Ga)(S, Se)2 thin-film surfaces: Modifying the chemical and electronic structure

Mezher, Michelle; Mansfield, Lorelle M.; Horsley, Kimberly; Blum, Monika; Wieting, Robert; Weinhardt, Lothar; Ramanathan, Kannan; Heske, Clemens

doi:10.1063/1.4998445

KF post-deposition treatment of industrial Cu(In, Ga)(S, Se)₂ thin-film surfaces: Modifying the chemical and electronic structure

Journal Article · Mon Aug 14 00:00:00 EDT 2017 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4998445· OSTI ID:1379465

Mezher, Michelle ^[1]; ^[2]; Horsley, Kimberly ^[3]; Blum, Monika ^[1]; Wieting, Robert ^[4]; Weinhardt, Lothar ^[5]; Ramanathan, Kannan ^[4]; ^[5]

Univ. of Nevada, Las Vegas (UNLV), Las Vegas, NV (United States)
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Univ. of Nevada, Las Vegas (UNLV), Las Vegas, NV (United States); Univ. of Hawaii at Manoa, Honolulu, HI (United States)
STION, San Jose, CA (United States)
Univ. of Nevada, Las Vegas (UNLV), Las Vegas, NV (United States); Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen (Germany); Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany)

The chemical and electronic structures of industrial chalcopyrite photovoltaic absorbers after KF post-deposition treatment (KF-PDT) are investigated using electron spectroscopies to probe the occupied and unoccupied electronic states. In contrast to a variety of recent publications on the impact of KF-PDT, this study focuses on industrial Cu(In,Ga)(S,Se)₂ absorbers that also contain sulfur at the surface. We find that the KF-PDT removes surface adsorbates and oxides and also observe a change in the S/Se ratio. Furthermore, the KF-PDT leads to a Cu reduction at the surface but to a much lower degree than the strongly Cu-depleted or even Cu-free surfaces reported for (non-industrial) sulfur-free Cu(In,Ga)Se₂ absorbers. Furthermore, the valence band maximum at the surface is found at a lower energy compared to the untreated absorber, and the conduction band minimum is found at a higher energy, overall revealing a widening of the bandgap in the surface region.

View Accepted Manuscript (DOE)

Research Organization:: National Renewable Energy Laboratory (NREL), Golden, CO (United States)

Sponsoring Organization:: USDOE; USDOE Office of Energy Efficiency and Renewable Energy (EERE), Solar Energy Technologies Office (EE-4S), SunShot Foundational Program to Advance Cell Efficiency (F-PACE)

Grant/Contract Number:: AC36-08GO28308

OSTI ID:: 1379465

Alternate ID(s):: OSTI ID: 1374925

Report Number(s):: NREL/JA--5K00-70059

Journal Information:: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 7 Vol. 111; ISSN 0003-6951

Publisher:: American Institute of Physics (AIP)Copyright Statement

Country of Publication:: United States

Language:: English

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Alkali Postdeposition Treatment-Induced Changes of the Chemical and Electronic Structure of Cu(In,Ga)Se₂ Thin-Film Solar Cell Absorbers: A First-Principle Perspective Malitckaya, Maria; Kunze, Thomas; Komsa, Hannu-Pekka ACS Applied Materials & Interfaces, Vol. 11, Issue 3 https://doi.org/10.1021/acsami.8b18216	journal	December 2018
Surface and Interface Properties in Thin‐Film Solar Cells: Using Soft X‐rays and Electrons to Unravel the Electronic and Chemical Structure Weinhardt, Lothar; Hauschild, Dirk; Heske, Clemens Advanced Materials, Vol. 31, Issue 26 https://doi.org/10.1002/adma.201806660	journal	February 2019
Effect of Cu Content on Post‐Sulfurization of Cu(In,Ga)Se ₂ Films and Corresponding Solar Cell Performance Keller, Jan; Bilousov, Oleksandr V.; Wallin, Erik physica status solidi (a), Vol. 216, Issue 20 https://doi.org/10.1002/pssa.201900472	journal	August 2019
Observation and manipulation of CIGSe phase formation in a two stage sequential process Schönherr, Sven; Schöppe, Philipp; Kusch, Alexander Applied Physics Letters, Vol. 115, Issue 14 https://doi.org/10.1063/1.5119189	journal	September 2019
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Surface and Interface Properties in Thin-Film Solar Cells: Using Soft X-rays and Electrons to Unravel the Electronic and Chemical Structure Weinhardt, Lothar; Hauschild, Dirk; Heske, Clemens Karlsruhe https://doi.org/10.5445/ir/1000093239	text	January 2019

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