All-Inorganic CsPbI3 Quantum Dot Solar Cells with Efficiency over 16% by Defect Control

Linlin ZHANG; Cuiting KANG; Guizhi ZHANG; Zhenxiao PAN; Zhaoshuai HUANG; Shuaihang XU; Huashang RAO; Hongbin LIU; Shengfan WU; Xin WU; Xiaosong LI; Zonglong ZHU; Xinhua ZHONG; Alex K.Y. JEN

doi:10.1002/adfm.202005930

All-Inorganic CsPbI₃ Quantum Dot Solar Cells with Efficiency over 16% by Defect Control

Linlin ZHANG, Cuiting KANG, Guizhi ZHANG, Zhenxiao PAN^*, Zhaoshuai HUANG, Shuaihang XU, Huashang RAO, Hongbin LIU, Shengfan WU, Xin WU, Xiaosong LI, Zonglong ZHU^*, Xinhua ZHONG^*, Alex K.Y. JEN

^*Corresponding author for this work

Research output: Journal Publications › Journal Article (refereed) › peer-review

117 Citations (Scopus)

Abstract

All-inorganic CsPbI₃ quantum dots (QDs) have shown great potential in photovoltaic applications. However, their performance has been limited by defects and phase stability. Herein, an anion/cation synergy strategy to improve the structural stability of CsPbI₃ QDs and reduce the pivotal iodine vacancy (V_I) defect states is proposed. The Zn-doped CsPbI₃ (Zn:CsPbI₃) QDs have been successfully synthesized employing ZnI₂ as the dopant to provide Zn²⁺ and extra I⁻. Theoretical calculations and experimental results demonstrate that the Zn:CsPbI₃ QDs show better thermodynamic stability and higher photoluminescence quantum yield (PLQY) compared to the pristine CsPbI₃ QDs. The doping of Zn in CsPbI₃ QDs increases the formation energy and Goldschmidt tolerance factor, thereby improving the thermodynamic stability. The additional I⁻ helps to reduce the V_I defects during the synthesis of CsPbI₃ QDs, resulting in the higher PLQY. More importantly, the synergistic effect of Zn²⁺ and I⁻ in CsPbI₃ QDs can prevent the iodine loss during the fabrication of CsPbI₃ QD film, inhibiting the formation of new V_I defect states in the construction of solar cells. Consequently, the anion/cation synergy strategy affords the CsPbI₃ quantum dot solar cells (QDSC) a power conversion efficiency over 16%, which is among the best efficiencies for perovskite QDSCs.

Original language	English
Article number	2005930
Journal	Advanced Functional Materials
Volume	31
Issue number	4
Early online date	21 Oct 2020
DOIs	https://doi.org/10.1002/adfm.202005930
Publication status	Published - 22 Jan 2021
Externally published	Yes

Bibliographical note

Publisher Copyright:
© 2020 Wiley-VCH GmbH

Funding

L.Z., C.K., and G.Z. contributed equally to this work. This research was supported by the National Natural Science Foundation of China (NFSC nos. 51732004, 21703071, 21805093, and 21975083). A.K.-Y.J. and Z.Z. thank the CityU start-up fund (7200587 and 9610421) and Innovation and Technology Fund (ITS/497/18FP and GHP/021/18SZ). Z.Z. also thanks the Natural Science Foundation of Guangdong Province (2019A1515010761) and the Teaching Start-Up Grant of City University of Hong Kong (6000672). Theoretical research of surface traps was supported by the University of Washington Molecular Engineering Materials Center funded by the NSF (DMR-1719797 and CHE-1856210 to X.L.). This work was facilitated through the use of advanced computational, storage, and networking infrastructure provided by the Hyak supercomputer system and was funded by the STF at the University of Washington and the National Science Foundation (MRI-1624430).

Keywords

CsPbI quantum dots
defect states
high efficiencies
solar cells
stabilities
zinc dopings

UN SDGs

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

Access to Document

10.1002/adfm.202005930

Cite this

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title = "All-Inorganic CsPbI3 Quantum Dot Solar Cells with Efficiency over 16% by Defect Control",

abstract = "All-inorganic CsPbI3 quantum dots (QDs) have shown great potential in photovoltaic applications. However, their performance has been limited by defects and phase stability. Herein, an anion/cation synergy strategy to improve the structural stability of CsPbI3 QDs and reduce the pivotal iodine vacancy (VI) defect states is proposed. The Zn-doped CsPbI3 (Zn:CsPbI3) QDs have been successfully synthesized employing ZnI2 as the dopant to provide Zn2+ and extra I−. Theoretical calculations and experimental results demonstrate that the Zn:CsPbI3 QDs show better thermodynamic stability and higher photoluminescence quantum yield (PLQY) compared to the pristine CsPbI3 QDs. The doping of Zn in CsPbI3 QDs increases the formation energy and Goldschmidt tolerance factor, thereby improving the thermodynamic stability. The additional I− helps to reduce the VI defects during the synthesis of CsPbI3 QDs, resulting in the higher PLQY. More importantly, the synergistic effect of Zn2+ and I− in CsPbI3 QDs can prevent the iodine loss during the fabrication of CsPbI3 QD film, inhibiting the formation of new VI defect states in the construction of solar cells. Consequently, the anion/cation synergy strategy affords the CsPbI3 quantum dot solar cells (QDSC) a power conversion efficiency over 16%, which is among the best efficiencies for perovskite QDSCs.",

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T1 - All-Inorganic CsPbI3 Quantum Dot Solar Cells with Efficiency over 16% by Defect Control

AU - ZHANG, Linlin

AU - KANG, Cuiting

AU - ZHANG, Guizhi

AU - PAN, Zhenxiao

AU - HUANG, Zhaoshuai

AU - XU, Shuaihang

AU - RAO, Huashang

AU - LIU, Hongbin

AU - WU, Shengfan

AU - WU, Xin

AU - LI, Xiaosong

AU - ZHU, Zonglong

AU - ZHONG, Xinhua

AU - JEN, Alex K.Y.

PY - 2021/1/22

Y1 - 2021/1/22

N2 - All-inorganic CsPbI3 quantum dots (QDs) have shown great potential in photovoltaic applications. However, their performance has been limited by defects and phase stability. Herein, an anion/cation synergy strategy to improve the structural stability of CsPbI3 QDs and reduce the pivotal iodine vacancy (VI) defect states is proposed. The Zn-doped CsPbI3 (Zn:CsPbI3) QDs have been successfully synthesized employing ZnI2 as the dopant to provide Zn2+ and extra I−. Theoretical calculations and experimental results demonstrate that the Zn:CsPbI3 QDs show better thermodynamic stability and higher photoluminescence quantum yield (PLQY) compared to the pristine CsPbI3 QDs. The doping of Zn in CsPbI3 QDs increases the formation energy and Goldschmidt tolerance factor, thereby improving the thermodynamic stability. The additional I− helps to reduce the VI defects during the synthesis of CsPbI3 QDs, resulting in the higher PLQY. More importantly, the synergistic effect of Zn2+ and I− in CsPbI3 QDs can prevent the iodine loss during the fabrication of CsPbI3 QD film, inhibiting the formation of new VI defect states in the construction of solar cells. Consequently, the anion/cation synergy strategy affords the CsPbI3 quantum dot solar cells (QDSC) a power conversion efficiency over 16%, which is among the best efficiencies for perovskite QDSCs.

AB - All-inorganic CsPbI3 quantum dots (QDs) have shown great potential in photovoltaic applications. However, their performance has been limited by defects and phase stability. Herein, an anion/cation synergy strategy to improve the structural stability of CsPbI3 QDs and reduce the pivotal iodine vacancy (VI) defect states is proposed. The Zn-doped CsPbI3 (Zn:CsPbI3) QDs have been successfully synthesized employing ZnI2 as the dopant to provide Zn2+ and extra I−. Theoretical calculations and experimental results demonstrate that the Zn:CsPbI3 QDs show better thermodynamic stability and higher photoluminescence quantum yield (PLQY) compared to the pristine CsPbI3 QDs. The doping of Zn in CsPbI3 QDs increases the formation energy and Goldschmidt tolerance factor, thereby improving the thermodynamic stability. The additional I− helps to reduce the VI defects during the synthesis of CsPbI3 QDs, resulting in the higher PLQY. More importantly, the synergistic effect of Zn2+ and I− in CsPbI3 QDs can prevent the iodine loss during the fabrication of CsPbI3 QD film, inhibiting the formation of new VI defect states in the construction of solar cells. Consequently, the anion/cation synergy strategy affords the CsPbI3 quantum dot solar cells (QDSC) a power conversion efficiency over 16%, which is among the best efficiencies for perovskite QDSCs.

KW - CsPbI quantum dots

KW - defect states

KW - high efficiencies

KW - solar cells

KW - stabilities

KW - zinc dopings

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M3 - Journal Article (refereed)

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