The effect of Na on Cu-K-In-Se thin film growth

Muzzillo, Christopher P.; Tong, Ho Ming; Anderson, Timothy J.

doi:10.1016/j.jcrysgro.2018.02.035

Title: The effect of Na on Cu-K-In-Se thin film growth

Abstract

Co-evaporation of Cu-KF-In-Se was performed on substrates with varied Na supply. Compositions of interest for photovoltaic absorbers were studied, with ratios of (K + Cu)/In ~ 0.85 and K/(K + Cu) ~ 0-0.57. Bare soda-lime glass (SLG) substrates had the highest Na supply as measured by secondary ion mass spectrometry, while SLG/Mo and SLG/SiO₂/Mo substrates led to 3x and 3000x less Na in the growing film, respectively. Increased Na supply favored Cu_1-xK_xInSe₂ (CKIS) alloy formation as proven by X-ray diffraction (XRD), while decreased Na supply favored the formation of CuInSe₂ + KInSe₂ mixed-phase films. Scanning electron microscopy and energy dispersive X-ray spectroscopy revealed the KInSe₂ precipitates to be readily recognizable planar crystals. Extrinsic KF addition during film growth promoted diffusion of Na out from the various substrates and into the growing film, in agreement with previous reports. Time-resolved photoluminescence showed enhanced minority carrier lifetimes for films with moderate K compositions (0.04 < K/(K + Cu) < 0.14) grown on SLG/Mo. Due to the relatively high detection limit of KInSe₂ by XRD and the low magnitude of chalcopyrite lattice shift for CKIS alloys with these compositions, it is unclear if the lifetime gains were associated with CKIS alloying, minor KInSe₂ content,more »« less

Authors:

Muzzillo, Christopher P. ^[1]; Tong, Ho Ming ^[2]; Anderson, Timothy J. ^[3]

Univ. of Florida, Gainesville, FL (United States); National Renewable Energy Lab. (NREL), Golden, CO (United States)
Univ. of Florida, Gainesville, FL (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Univ. of Florida, Gainesville, FL (United States)

Publication Date:: Tue Feb 27 00:00:00 EST 2018

Research Org.:: National Renewable Energy Lab. (NREL), Golden, CO (United States)

Sponsoring Org.:: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Solar Energy Technologies Office

OSTI Identifier:: 1427350

Report Number(s):: NREL/JA-5K00-71039
Journal ID: ISSN 0022-0248

Grant/Contract Number:: AC36-08GO28308

Resource Type:: Accepted Manuscript

Journal Name:: Journal of Crystal Growth

Additional Journal Information:: Journal Volume: 488; Journal Issue: C; Journal ID: ISSN 0022-0248

Publisher:: Elsevier

Country of Publication:: United States

Language:: English

Subject:: 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; crystal morphology; segregation; solid solutions; physical vapor deposition processes; alloys; semiconducting materials

Citation Formats


                    Muzzillo, Christopher P., Tong, Ho Ming, and Anderson, Timothy J. The effect of Na on Cu-K-In-Se thin film growth.  United States: N. p., 2018. 
Web.  doi:10.1016/j.jcrysgro.2018.02.035.

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                    Muzzillo, Christopher P., Tong, Ho Ming, & Anderson, Timothy J. The effect of Na on Cu-K-In-Se thin film growth.  United States.  https://doi.org/10.1016/j.jcrysgro.2018.02.035

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                    Muzzillo, Christopher P., Tong, Ho Ming, and Anderson, Timothy J. Tue .  
"The effect of Na on Cu-K-In-Se thin film growth".  United States.  https://doi.org/10.1016/j.jcrysgro.2018.02.035.  https://www.osti.gov/servlets/purl/1427350.

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@article{osti_1427350,

  title        = {The effect of Na on Cu-K-In-Se thin film growth},

  author       = {Muzzillo, Christopher P. and Tong, Ho Ming and Anderson, Timothy J.},

  abstractNote = {Co-evaporation of Cu-KF-In-Se was performed on substrates with varied Na supply. Compositions of interest for photovoltaic absorbers were studied, with ratios of (K + Cu)/In ~ 0.85 and K/(K + Cu) ~ 0-0.57. Bare soda-lime glass (SLG) substrates had the highest Na supply as measured by secondary ion mass spectrometry, while SLG/Mo and SLG/SiO2/Mo substrates led to 3x and 3000x less Na in the growing film, respectively. Increased Na supply favored Cu1-xKxInSe2 (CKIS) alloy formation as proven by X-ray diffraction (XRD), while decreased Na supply favored the formation of CuInSe2 + KInSe2 mixed-phase films. Scanning electron microscopy and energy dispersive X-ray spectroscopy revealed the KInSe2 precipitates to be readily recognizable planar crystals. Extrinsic KF addition during film growth promoted diffusion of Na out from the various substrates and into the growing film, in agreement with previous reports. Time-resolved photoluminescence showed enhanced minority carrier lifetimes for films with moderate K compositions (0.04 < K/(K + Cu) < 0.14) grown on SLG/Mo. Due to the relatively high detection limit of KInSe2 by XRD and the low magnitude of chalcopyrite lattice shift for CKIS alloys with these compositions, it is unclear if the lifetime gains were associated with CKIS alloying, minor KInSe2 content, or both. The identified Na-K interdependency can be used to engineer alkali metal bonding in Cu(In,Ga)(Se,S)2 absorbers to optimize both initial and long-term photovoltaic power generation.},

  doi          = {10.1016/j.jcrysgro.2018.02.035},

  journal      = {Journal of Crystal Growth},

  number       = C,

  volume       = 488,

  place        = {United States},

  year         = {Tue Feb 27 00:00:00 EST 2018},

  month        = {Tue Feb 27 00:00:00 EST 2018}

}

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https://doi.org/10.1016/j.jcrysgro.2018.02.035

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Cited by: 5 works

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Figures / Tables:

Fig. 1: Plan view (top) and cross-sectional (bottom) SEM micrographs of CuInSe₂ (CKIS with K/(K+Cu), or x ~ 0) films on Mo (left) and SLG (right) substrates.

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Works referenced in this record:

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Works referencing / citing this record:

Revealing the beneficial role of K in grain interiors, grain boundaries, and at the buffer interface for highly efficient CuInSe ₂ solar cells
journal, June 2018

Muzzillo, Christopher P.; Poplawsky, Jonathan D.; Tong, Ho Ming
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Figures / Tables found in this record:

Fig. 1 (p. 7)

Fig. 2 (p. 8)

Table I: Part 1 (p. 8)

Fig. 3 (p. 9)

Table I: Part 2 (p. 9)

Figures/Tables have been extracted from DOE-funded journal article accepted manuscripts.

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Title: The effect of Na on Cu-K-In-Se thin film growth

Abstract

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Surface modification of CIGS film by annealing and its effect on the band structure and photovoltaic properties of CIGS solar cells
journal, January 2015

The impact of alkali elements on the degradation of CIGS solar cells: Degradation of CIGS solar cells
journal, April 2015

Properties of Cu1−x K x InSe2 alloys
journal, April 2016

The effect of Ga content on the selenization of co-evaporated CuGa/In films and their photovoltaic performance
conference, June 2014

Differences between CuGa/In and Cu/Ga/In films for selenization
conference, June 2015

Na-induced variations in the structural, optical, and electrical properties of Cu(In,Ga)Se2 thin films
journal, August 2009

Diffusion of indium and gallium in Cu(In,Ga)Se2 thin film solar cells
journal, September 2003

Fiber-fed time-resolved photoluminescence for reduced process feedback time on thin-film photovoltaics
journal, January 2015

Photovoltaic properties of selenized CuGa/In films with varied compositions
conference, June 2016

Effect of Alkali Metal Atom Doping on the CuInSe ₂ -Based Solar Cell Absorber
journal, July 2017

KF post deposition treatment in co-evaporated Cu(In,Ga)Se ₂ thin film solar cells: Beneficial or detrimental effect induced by the absorber characteristics
journal, July 2017

Surface and bulk effects of K in highly efficient Cu1-xKxInSe2 solar cells
journal, October 2018

Review of grain interior, grain boundary, and interface effects of K in CIGS solar cells: Mechanisms for performance enhancement
journal, December 2017

Revealing the beneficial role of K in grain interiors, grain boundaries, and at the buffer interface for highly efficient CuInSe ₂ solar cells
journal, June 2018