Control of doping in Cu2SnS3 through defects and alloying

Lauryn L. Baranowski, Pawel Zawadzki, Steven Christensen, Dennis Nordlund, Stephan Lany, Adele C. Tamboli, Lynn Gedvilas, David S. Ginley, William Tumas, Eric S. Toberer, Andriy Zakutayev

Research output: Contribution to journalArticle

89 Citations (Scopus)

Abstract

As the world's demand for energy grows, the search for cost competitive and earth abundant thin film photovoltaic absorbers is becoming increasingly important. A promising approach to tackle this challenge is through thin film photovoltaics made of elements that are abundant in the Earth's crust. In this work, we focus on Cu2SnS3, a promising earth abundant absorber material. Recent publications have presented 3% and 6% device efficiencies using Cu2SnS3-based absorber materials and alloys, respectively. However, little is understood about the fundamental defect and doping physics of this material, which is needed for further improvements in device performance. Here, we identify the origins of the changes in doping in sputtered cubic Cu2SnS3 thin films using combinatorial experiments and first-principles theory. Experimentally, we find that the cubic Cu2SnS3 has a large phase width and that the electrical conductivity increases with increasing Cu and S content in the films, which cannot be fully explained by the theoretical point defect model. Instead, theoretical calcuations suggest that under Cu-rich conditions alloying with an isostructural metallic Cu3SnS4 phase occurs, causing high levels of p-type doping; this theory is consistent with experimental Raman and NEXAFS spectroscopy data. These experimental and theoretical works lead to the conclusion that Cu2SnS3 films must be grown both S-poor and Cu-poor in order to achieve moderate hole concentrations. These new insights enable the design of growth processes that target the desired carrier concentrations for solar cell fabrication. Using the strategies described above, we have been able to tune the carrier concentration over >3 orders of magnitude and achieve films with p-type doping of 1018 cm-3, facilitating future device integration of these films.

Original languageEnglish
Pages (from-to)4951-4959
Number of pages9
JournalChemistry of Materials
Volume26
Issue number17
DOIs
Publication statusPublished - Sep 9 2014

Fingerprint

Alloying
Doping (additives)
Defects
Earth (planet)
Thin films
Carrier concentration
X ray absorption near edge structure spectroscopy
Hole concentration
Point defects
Raman spectroscopy
Solar cells
Physics
Fabrication
Costs
Experiments

ASJC Scopus subject areas

  • Materials Chemistry
  • Chemical Engineering(all)
  • Chemistry(all)

Cite this

Baranowski, L. L., Zawadzki, P., Christensen, S., Nordlund, D., Lany, S., Tamboli, A. C., ... Zakutayev, A. (2014). Control of doping in Cu2SnS3 through defects and alloying. Chemistry of Materials, 26(17), 4951-4959. https://doi.org/10.1021/cm501339v

Control of doping in Cu2SnS3 through defects and alloying. / Baranowski, Lauryn L.; Zawadzki, Pawel; Christensen, Steven; Nordlund, Dennis; Lany, Stephan; Tamboli, Adele C.; Gedvilas, Lynn; Ginley, David S.; Tumas, William; Toberer, Eric S.; Zakutayev, Andriy.

In: Chemistry of Materials, Vol. 26, No. 17, 09.09.2014, p. 4951-4959.

Research output: Contribution to journalArticle

Baranowski, LL, Zawadzki, P, Christensen, S, Nordlund, D, Lany, S, Tamboli, AC, Gedvilas, L, Ginley, DS, Tumas, W, Toberer, ES & Zakutayev, A 2014, 'Control of doping in Cu2SnS3 through defects and alloying', Chemistry of Materials, vol. 26, no. 17, pp. 4951-4959. https://doi.org/10.1021/cm501339v
Baranowski LL, Zawadzki P, Christensen S, Nordlund D, Lany S, Tamboli AC et al. Control of doping in Cu2SnS3 through defects and alloying. Chemistry of Materials. 2014 Sep 9;26(17):4951-4959. https://doi.org/10.1021/cm501339v
Baranowski, Lauryn L. ; Zawadzki, Pawel ; Christensen, Steven ; Nordlund, Dennis ; Lany, Stephan ; Tamboli, Adele C. ; Gedvilas, Lynn ; Ginley, David S. ; Tumas, William ; Toberer, Eric S. ; Zakutayev, Andriy. / Control of doping in Cu2SnS3 through defects and alloying. In: Chemistry of Materials. 2014 ; Vol. 26, No. 17. pp. 4951-4959.
@article{db75dcd62699498ea61e8619745d45b6,
title = "Control of doping in Cu2SnS3 through defects and alloying",
abstract = "As the world's demand for energy grows, the search for cost competitive and earth abundant thin film photovoltaic absorbers is becoming increasingly important. A promising approach to tackle this challenge is through thin film photovoltaics made of elements that are abundant in the Earth's crust. In this work, we focus on Cu2SnS3, a promising earth abundant absorber material. Recent publications have presented 3{\%} and 6{\%} device efficiencies using Cu2SnS3-based absorber materials and alloys, respectively. However, little is understood about the fundamental defect and doping physics of this material, which is needed for further improvements in device performance. Here, we identify the origins of the changes in doping in sputtered cubic Cu2SnS3 thin films using combinatorial experiments and first-principles theory. Experimentally, we find that the cubic Cu2SnS3 has a large phase width and that the electrical conductivity increases with increasing Cu and S content in the films, which cannot be fully explained by the theoretical point defect model. Instead, theoretical calcuations suggest that under Cu-rich conditions alloying with an isostructural metallic Cu3SnS4 phase occurs, causing high levels of p-type doping; this theory is consistent with experimental Raman and NEXAFS spectroscopy data. These experimental and theoretical works lead to the conclusion that Cu2SnS3 films must be grown both S-poor and Cu-poor in order to achieve moderate hole concentrations. These new insights enable the design of growth processes that target the desired carrier concentrations for solar cell fabrication. Using the strategies described above, we have been able to tune the carrier concentration over >3 orders of magnitude and achieve films with p-type doping of 1018 cm-3, facilitating future device integration of these films.",
author = "Baranowski, {Lauryn L.} and Pawel Zawadzki and Steven Christensen and Dennis Nordlund and Stephan Lany and Tamboli, {Adele C.} and Lynn Gedvilas and Ginley, {David S.} and William Tumas and Toberer, {Eric S.} and Andriy Zakutayev",
year = "2014",
month = "9",
day = "9",
doi = "10.1021/cm501339v",
language = "English",
volume = "26",
pages = "4951--4959",
journal = "Chemistry of Materials",
issn = "0897-4756",
publisher = "American Chemical Society",
number = "17",

}

TY - JOUR

T1 - Control of doping in Cu2SnS3 through defects and alloying

AU - Baranowski, Lauryn L.

AU - Zawadzki, Pawel

AU - Christensen, Steven

AU - Nordlund, Dennis

AU - Lany, Stephan

AU - Tamboli, Adele C.

AU - Gedvilas, Lynn

AU - Ginley, David S.

AU - Tumas, William

AU - Toberer, Eric S.

AU - Zakutayev, Andriy

PY - 2014/9/9

Y1 - 2014/9/9

N2 - As the world's demand for energy grows, the search for cost competitive and earth abundant thin film photovoltaic absorbers is becoming increasingly important. A promising approach to tackle this challenge is through thin film photovoltaics made of elements that are abundant in the Earth's crust. In this work, we focus on Cu2SnS3, a promising earth abundant absorber material. Recent publications have presented 3% and 6% device efficiencies using Cu2SnS3-based absorber materials and alloys, respectively. However, little is understood about the fundamental defect and doping physics of this material, which is needed for further improvements in device performance. Here, we identify the origins of the changes in doping in sputtered cubic Cu2SnS3 thin films using combinatorial experiments and first-principles theory. Experimentally, we find that the cubic Cu2SnS3 has a large phase width and that the electrical conductivity increases with increasing Cu and S content in the films, which cannot be fully explained by the theoretical point defect model. Instead, theoretical calcuations suggest that under Cu-rich conditions alloying with an isostructural metallic Cu3SnS4 phase occurs, causing high levels of p-type doping; this theory is consistent with experimental Raman and NEXAFS spectroscopy data. These experimental and theoretical works lead to the conclusion that Cu2SnS3 films must be grown both S-poor and Cu-poor in order to achieve moderate hole concentrations. These new insights enable the design of growth processes that target the desired carrier concentrations for solar cell fabrication. Using the strategies described above, we have been able to tune the carrier concentration over >3 orders of magnitude and achieve films with p-type doping of 1018 cm-3, facilitating future device integration of these films.

AB - As the world's demand for energy grows, the search for cost competitive and earth abundant thin film photovoltaic absorbers is becoming increasingly important. A promising approach to tackle this challenge is through thin film photovoltaics made of elements that are abundant in the Earth's crust. In this work, we focus on Cu2SnS3, a promising earth abundant absorber material. Recent publications have presented 3% and 6% device efficiencies using Cu2SnS3-based absorber materials and alloys, respectively. However, little is understood about the fundamental defect and doping physics of this material, which is needed for further improvements in device performance. Here, we identify the origins of the changes in doping in sputtered cubic Cu2SnS3 thin films using combinatorial experiments and first-principles theory. Experimentally, we find that the cubic Cu2SnS3 has a large phase width and that the electrical conductivity increases with increasing Cu and S content in the films, which cannot be fully explained by the theoretical point defect model. Instead, theoretical calcuations suggest that under Cu-rich conditions alloying with an isostructural metallic Cu3SnS4 phase occurs, causing high levels of p-type doping; this theory is consistent with experimental Raman and NEXAFS spectroscopy data. These experimental and theoretical works lead to the conclusion that Cu2SnS3 films must be grown both S-poor and Cu-poor in order to achieve moderate hole concentrations. These new insights enable the design of growth processes that target the desired carrier concentrations for solar cell fabrication. Using the strategies described above, we have been able to tune the carrier concentration over >3 orders of magnitude and achieve films with p-type doping of 1018 cm-3, facilitating future device integration of these films.

UR - http://www.scopus.com/inward/record.url?scp=84907972557&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84907972557&partnerID=8YFLogxK

U2 - 10.1021/cm501339v

DO - 10.1021/cm501339v

M3 - Article

AN - SCOPUS:84907972557

VL - 26

SP - 4951

EP - 4959

JO - Chemistry of Materials

JF - Chemistry of Materials

SN - 0897-4756

IS - 17

ER -