Improving the charge separation and collection at the buffer/absorber interface by double-layered Mn-substituted CZTS

Stener Lie; Mario Indra Sandi; Ying Fan Tay; Wenjie Li; Joel Ming Rui Tan; Douglas M. Bishop; Oki Gunawan; Lydia Helena Wong

doi:10.1016/j.solmat.2018.05.052

Improving the charge separation and collection at the buffer/absorber interface by double-layered Mn-substituted CZTS

Stener Lie, Mario Indra Sandi, Ying Fan Tay, Wenjie Li, Joel Ming Rui Tan, Douglas M. Bishop, Oki Gunawan, Lydia Helena Wong^*

^*Corresponding author for this work

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

28 Citations (Scopus)

Abstract

A non-ideal buffer-absorber interface due to interface recombination is one of the limitations in Cu₂ZnSnS₄ (CZTS) solar cells. An absorber gradient using partial cation-substitution is one possible solution to this issue by reducing interface recombination sites and improving band alignment. Partial substitution of Zn with Mn is a potentially attractive concept owing to its abundance as well as similar size and electronic properties compared to Zn. In this study, Cu₂Mn_xZn_1-xSnS₄ (CMZTS) thin film were fabricated by a sol-gel spin coating technique to understand the effect of Mn on the device performance. X-ray diffraction (XRD) and Raman analysis confirm Mn substitution for Zn in the crystal lattice of Cu₂ZnSnS₄ (CZTS) with no secondary phases detected for x ≤ 0.4. Enhancement of short circuit current (Jsc) in Cu₂Mn_0.15Zn_0.85SnS₄ has led to improved efficiency in comparison with CZTS. Since external quantum efficiency (EQE) indicates the short wavelength collection as the main reason for the improved Jsc, we designed a double layered structure of CZTS as bottom layer and CM_0.15Z_0.85TS as top layer. With this structure, we obtained our best performance cell with power conversion efficiency (PCE) of 5.73% and Jsc of 17.86 mA/cm². The improved Jsc is attributed to increased depletion width and higher activation energy of the limiting recombination mechanism as shown by capacitance-voltage and temperature dependent current-voltage measurements. Our study concludes that CM_0.15Z_0.85TS top layer improves the interface quality of the p-n junction and may be an alternative method to improve the performance of CZTS solar cells.

Original language	English
Pages (from-to)	351-358
Number of pages	8
Journal	Solar Energy Materials and Solar Cells
Volume	185
DOIs	https://doi.org/10.1016/j.solmat.2018.05.052
Publication status	Published - Oct 2018
Externally published	Yes

Bibliographical note

Publisher Copyright:
© 2018

ASJC Scopus Subject Areas

Electronic, Optical and Magnetic Materials
Renewable Energy, Sustainability and the Environment
Surfaces, Coatings and Films

Keywords

Cation substitution
Earth abundant materials
Interfacial engineering
Photovoltaics
Thin film

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

Access to Document

10.1016/j.solmat.2018.05.052

Cite this

@article{58803bdbe70e447895d1a768366fbd81,

title = "Improving the charge separation and collection at the buffer/absorber interface by double-layered Mn-substituted CZTS",

abstract = "A non-ideal buffer-absorber interface due to interface recombination is one of the limitations in Cu2ZnSnS4 (CZTS) solar cells. An absorber gradient using partial cation-substitution is one possible solution to this issue by reducing interface recombination sites and improving band alignment. Partial substitution of Zn with Mn is a potentially attractive concept owing to its abundance as well as similar size and electronic properties compared to Zn. In this study, Cu2MnxZn1-xSnS4 (CMZTS) thin film were fabricated by a sol-gel spin coating technique to understand the effect of Mn on the device performance. X-ray diffraction (XRD) and Raman analysis confirm Mn substitution for Zn in the crystal lattice of Cu2ZnSnS4 (CZTS) with no secondary phases detected for x ≤ 0.4. Enhancement of short circuit current (Jsc) in Cu2Mn0.15Zn0.85SnS4 has led to improved efficiency in comparison with CZTS. Since external quantum efficiency (EQE) indicates the short wavelength collection as the main reason for the improved Jsc, we designed a double layered structure of CZTS as bottom layer and CM0.15Z0.85TS as top layer. With this structure, we obtained our best performance cell with power conversion efficiency (PCE) of 5.73% and Jsc of 17.86 mA/cm2. The improved Jsc is attributed to increased depletion width and higher activation energy of the limiting recombination mechanism as shown by capacitance-voltage and temperature dependent current-voltage measurements. Our study concludes that CM0.15Z0.85TS top layer improves the interface quality of the p-n junction and may be an alternative method to improve the performance of CZTS solar cells.",

keywords = "Cation substitution, Earth abundant materials, Interfacial engineering, Photovoltaics, Thin film",

author = "Stener Lie and Sandi, {Mario Indra} and Tay, {Ying Fan} and Wenjie Li and Tan, {Joel Ming Rui} and Bishop, {Douglas M.} and Oki Gunawan and Wong, {Lydia Helena}",

note = "Publisher Copyright: {\textcopyright} 2018",

year = "2018",

month = oct,

doi = "10.1016/j.solmat.2018.05.052",

language = "English",

volume = "185",

pages = "351--358",

journal = "Solar Energy Materials and Solar Cells",

issn = "0927-0248",

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T1 - Improving the charge separation and collection at the buffer/absorber interface by double-layered Mn-substituted CZTS

AU - Lie, Stener

AU - Sandi, Mario Indra

AU - Tay, Ying Fan

AU - Li, Wenjie

AU - Tan, Joel Ming Rui

AU - Bishop, Douglas M.

AU - Gunawan, Oki

AU - Wong, Lydia Helena

PY - 2018/10

Y1 - 2018/10

N2 - A non-ideal buffer-absorber interface due to interface recombination is one of the limitations in Cu2ZnSnS4 (CZTS) solar cells. An absorber gradient using partial cation-substitution is one possible solution to this issue by reducing interface recombination sites and improving band alignment. Partial substitution of Zn with Mn is a potentially attractive concept owing to its abundance as well as similar size and electronic properties compared to Zn. In this study, Cu2MnxZn1-xSnS4 (CMZTS) thin film were fabricated by a sol-gel spin coating technique to understand the effect of Mn on the device performance. X-ray diffraction (XRD) and Raman analysis confirm Mn substitution for Zn in the crystal lattice of Cu2ZnSnS4 (CZTS) with no secondary phases detected for x ≤ 0.4. Enhancement of short circuit current (Jsc) in Cu2Mn0.15Zn0.85SnS4 has led to improved efficiency in comparison with CZTS. Since external quantum efficiency (EQE) indicates the short wavelength collection as the main reason for the improved Jsc, we designed a double layered structure of CZTS as bottom layer and CM0.15Z0.85TS as top layer. With this structure, we obtained our best performance cell with power conversion efficiency (PCE) of 5.73% and Jsc of 17.86 mA/cm2. The improved Jsc is attributed to increased depletion width and higher activation energy of the limiting recombination mechanism as shown by capacitance-voltage and temperature dependent current-voltage measurements. Our study concludes that CM0.15Z0.85TS top layer improves the interface quality of the p-n junction and may be an alternative method to improve the performance of CZTS solar cells.

AB - A non-ideal buffer-absorber interface due to interface recombination is one of the limitations in Cu2ZnSnS4 (CZTS) solar cells. An absorber gradient using partial cation-substitution is one possible solution to this issue by reducing interface recombination sites and improving band alignment. Partial substitution of Zn with Mn is a potentially attractive concept owing to its abundance as well as similar size and electronic properties compared to Zn. In this study, Cu2MnxZn1-xSnS4 (CMZTS) thin film were fabricated by a sol-gel spin coating technique to understand the effect of Mn on the device performance. X-ray diffraction (XRD) and Raman analysis confirm Mn substitution for Zn in the crystal lattice of Cu2ZnSnS4 (CZTS) with no secondary phases detected for x ≤ 0.4. Enhancement of short circuit current (Jsc) in Cu2Mn0.15Zn0.85SnS4 has led to improved efficiency in comparison with CZTS. Since external quantum efficiency (EQE) indicates the short wavelength collection as the main reason for the improved Jsc, we designed a double layered structure of CZTS as bottom layer and CM0.15Z0.85TS as top layer. With this structure, we obtained our best performance cell with power conversion efficiency (PCE) of 5.73% and Jsc of 17.86 mA/cm2. The improved Jsc is attributed to increased depletion width and higher activation energy of the limiting recombination mechanism as shown by capacitance-voltage and temperature dependent current-voltage measurements. Our study concludes that CM0.15Z0.85TS top layer improves the interface quality of the p-n junction and may be an alternative method to improve the performance of CZTS solar cells.

KW - Cation substitution

KW - Earth abundant materials

KW - Interfacial engineering

KW - Photovoltaics

KW - Thin film

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U2 - 10.1016/j.solmat.2018.05.052

DO - 10.1016/j.solmat.2018.05.052

M3 - Article

AN - SCOPUS:85048484594

SN - 0927-0248

VL - 185

SP - 351

EP - 358

JO - Solar Energy Materials and Solar Cells

JF - Solar Energy Materials and Solar Cells

ER -

Improving the charge separation and collection at the buffer/absorber interface by double-layered Mn-substituted CZTS

Abstract

Bibliographical note

ASJC Scopus Subject Areas

Keywords

UN SDGs

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