Dual effective dopant based hole transport layer for stable and efficient perovskite solar cells

doi:10.1016/j.nanoen.2020.104673

Nano Energy

Volume 72, June 2020, 104673

https://doi.org/10.1016/j.nanoen.2020.104673 Get rights and content

Highlights

•
A 1,4-dihydropyrrolo[3,2-b]pyrrole (PPY) core units based small molecular material termed PFPPY is reported.
•
PFPPY is a dual functional material, it can simultaneously work as p-type dopant and defect passivator.
•
The PFPPY based device achieves a higher PCE of 21.38%, and maintain 90% of its initial PCE after 600 h in 40–50% RH.

Abstract

Conventionally, the hydroscopic nature of Li-TFSI and low boiling point of t-BP are considered as the primary limitations of hole transport layer (HTL), ultimately affecting the power conversion efficiency (PCE) and long-term stability of perovskite solar cell (PSC). To better stress these problems, a dual functional dopant termed PFPPY is reported. The in-depth operating mechanism of PFPPY with Spiro-OMeTAD, its profound effects on overall photovoltaic performance and device physics are systematically investigated. It is observed PFPPY can simultaneously take place of t-BP and FK209 in conventional HTL. By employing PFPPY as dopant cooperating with Spiro-OMeTAD, a higher PCE of 21.38% is achieved, compared with the reference device based on t-BP and FK209-doped Spiro-OMeTAD (19.69%). More importantly, the unencapsulated PFPPY-doped device shows greatly improved stability, maintaining over 90% of its initial PCE after 600 h in 40–50% RH. These findings provide a new strategy to optimize the HTL composition for efficient and stable PSCs.

Graphical abstract

A dual functional dopant termed PFPPY is designed, and successfully applied into hole transport layer of perovskite solar cell, achieving a high power conversion efficiency of 21.38% and good long-term stability.

Section snippets

CRediT authorship contribution statement

Govindasamy Sathiyan: Investigation, Methodology, Writing - original draft. Ali Asgher Syed: Investigation, Methodology, Writing - original draft. Cheng Chen: Project administration, Supervision, Writing - review & editing. Cheng Wu: Methodology, Formal analysis. Li Tao: Investigation, Software. Xingdong Ding: Formal analysis. Yawei Miao: Formal analysis. Gongqiang Li: Software, Formal analysis. Ming Cheng: Conceptualization, Data curation, Resources, Writing - review & editing. Liming Ding:

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgements

This work was financially supported by the National Natural Science Foundation of China (Grants 21805114, 21905119), Natural Science Foundation of Jiangsu Province (BK20180867, BK20180869), China Postdoctoral Science Foundation (2019M651741), Top talents in Jiangsu province (XNY066), the Jiangsu University Foundation (17JDG032, 17JDG031), High-tech Research Key laboratory of Zhenjiang (SS2018002), the State Key Laboratory of Fine Chemicals (KF1902), the high-performance computing platform of

Govindasamy Sathiyan is currently a Postdoctoral Fellow at Jiangsu University, China. He received his Ph.D. degree from VIT University, Vellore, India in July 2017. He had worked as SERB-National Post-Doctoral fellow in Department of Chemistry at Indian Institute of Technology Kanpur, India (2017–2019). His main research interests include the development of new organic functional materials for organic and perovskite solar cell applications.

References (41)

Z. Fang et al.
Sci. Bull.
(2019)
Z. Fang et al.
Sci. Bull.
(2019)
Q. Zeng et al.
Sci. Bull.
(2019)
N.-G. Park
Mater. Today
(2015)
X. Jia et al.
Sci. Bull.
(2019)
F. Zhang et al.
Joule
(2019)
B. Xu et al.
Inside Chem.
(2017)
L. Caliò et al.
Joule
(2018)
J.H. Heo et al.
Nat. Photon.
(2013)
M. Cheng et al.
Adv. Energy Mater.
(2017)

Q. Jiang et al.

Nat. Energy

(2016)

H. Zhou et al.

Science

(2014)

N.J. Jeon et al.

Nature

(2015)

H. Kim et al.

Adv. Energy Mater.

(2019)

K. Huang et al.

Adv. Energy Mater.

(2019)

J. Huang et al.

Nat. Rev. Mater.

(2017)

S.D. Stranks et al.

Science

(2013)

G. Xing et al.

Science

(2013)

C. Zuo et al.

Adv. Sci.

(2016)

Cited by (79)

A review on the engineering of hole-transporting materials for perovskite solar cells with high efficiency and high stability
2023, Dyes and Pigments
Perovskite solar cells (PSCs) are attracting attention as the most promising next-generation solar cells, recording high efficiency (25.7%) comparable to silicon solar cells. However, perovskite solar cells have difficulties in commercialization because of their low moisture and thermal stability.
In particular, 2,2′,7,7′-tetrakis(N,N-di-p-methoxyphenyl-amine)9,9′-spirobifluorene (spiro-OMeTAD) is a representative hole-transporting material (HTM), but it has inherently low hole mobility, so it is doped with dopants such as bis(trifluoromethane)sulfonimide lithium salt (Li-TFSI) and 4-tert-butylpyridine (tBP), which decrease the moisture and heat stability of the device. Therefore, for the commercialization of PSCs, the development of HTMs that make PSCs more efficient and stable is becoming more important.
This paper summarizes and discusses recent research progress on efficient and stable devices based on HTMs utilizing spiro-OMeTAD, small molecules, polymers, and functional polymers. In particular, the focus was on polymeric HTMs and functional polymeric HTMs.
We believe that this review will provide an accurate analysis of the research trend in HTMs and many insights for designing new HTMs and device systems for the commercialization of PSCs.
The role of different dopants of Spiro-OMeTAD hole transport material on the stability of perovskite solar cells: A mini review
2023, Vacuum
Perovskite solar cells (PSCs) have demonstrated rapid advancements in power conversion efficiency (PCE) in recent years, reaching 25.7% within a decade. However, the stability of PSCs lags behind in comparison, with short lifetimes being a major obstacle to commercialization. The various layers and interfaces within PSCs play a significant role in both PCE and stability. Spiro-OMeTAD is the most common hole-transport material (HTM) used in PSCs with n-i-p configuration, due to its high performance. However, Spiro-OMeTAD's bulky structure leads to low hole mobility and conductivity, making it an inefficient hole transporter. Doping Spiro-OMeTAD with specific organic and inorganic materials can increase PCE, but also introduces side effects on PSC stability. This review focuses on the effects of dopants on the stability of PSCs using Spiro-OMeTAD HTM and offers suggestions for enhancing PSC stability through dopant engineering for the eventual commercialization of PSCs.
Modifying the photoelectric performance of SnO<inf>2</inf> via D-arginine monohydrochloride for high-performance perovskite solar cells
2023, Journal of Alloys and Compounds
Although widely used as conducting substrates for solar cells, indium-tin oxide-based (ITO) electrodes’ potential for improvement of visible light transmittance is frequently overlooked of perovskite solar cells (PSCs) as most work focuses on the improvement of the working components (e.g., light absorber, etc) of the solar cells. This work shows a great improvement on solar cell performance by increasing the transmittance (up to 94 %) of the SnO₂/ITO electrode through adjusting the refractive index of the SnO₂ with D-arginine monohydrochloride (D-Arg) and introducing extra amino group, carboxyl groups and chloride ions to passivate interface defects. A 21.74 % of the championship power conversion efficiency is obtained, in comparison to the 19.58 % of the control device, and an increase in the short-circuit current from 23.26 to 24.51 mA cm⁻². Long-term stability is demonstrated with more than 86 % retention rate of the initial when stored in an air environment (10 % −25 % RH, 25 ℃), for 720 h. Therefore, this work provides a new and general approach in improving the performance of PSCs.
Study on the prevention of moisture intrusion of different shielding gas environments for stable perovskite solar cells
2023, Solar Energy
The stability and reliability of perovskite solar cells (PSCs) are severely affected by moisture. Therefore, it is very meaningful to study the barrier effect of gases with different compositions on moisture in a sealed environment. In this work, the stability of PSCs in a sealed environment filled with N₂, CO₂ with an external environment of 45 °C and 85% RH was investigated. After 240 h treatment, the PCE of the PSCs in the CO₂ sealed environment decayed to 71.1% of the initial value. The PCE of the PSCs in the N₂ sealed environment decayed to 51.8% of the initial value, while in the air environment as a control, the PCE decayed to 36.3% of the initial value. Through SEM, XRD film characterization and finite element simulation, it is found that both CO₂ and N₂ can be used as shielding gases to inhibit moisture intrusion, thereby slowing down the decay rate of perovskite solar cells. And CO₂ is more effective than N₂ in inhibiting moisture intrusion. On the one hand, CO₂ molecules are larger than N₂ molecules. When tiny gaps appear in the sealed environment, N₂ molecules can escape, but CO₂ cannot escape, which will lead to less moisture intrusion in the CO₂ sealed environment. On the other hand, when there are large gaps in the sealed environment, both N₂ and CO₂ can escape, because the diffusion coefficient of moisture in the N₂ sealed environment is larger, resulting in more moisture intrusion in the N₂ sealed environment.
Improved photovoltaic performance and stability of perovskite solar cells with device structure of (ITO/SnO<inf>2</inf>/CH<inf>3</inf>NH<inf>3</inf>PbI<inf>3</inf>/rGO+spiro-MeOTAD/Au)
2023, Materials Science and Engineering: B
The most challenging obstacles to practical application of perovskite solar cells (PSCs) are moisture sensitivity, and instability in ambient conditions. Recently, it has been seen that graphene or graphene based composites are the suitable candidate to improve the stability of PSCs. In present work, we reported the fabrication of lead halide PSCs by employing reduced graphene oxide (rGO) decorated spiro-MeOTAD as hole-transport material (rGO+HTM). Fabricated PSCs (ITO/SnO₂/CH₃NH₃PbI₃/rGO+HTM/Au) device exhibited good efficiency of 11.18% with excellent open circuit voltage (Voc) of 930 mV. Control device (ITO/SnO₂/CH₃NH₃PbI₃/HTM/Au) showed efficiency of 10.22% with Voc of 920 mV. Further, stability studies showed that presence of rGO improved the stability of developed PSCs and it retained more than 58.14% of its initial efficiency after 500 h. In case of control device, the efficiency was dropped from 10.22% to 4.4% (retained 43% efficiency after 500 h).
Interface engineering of organic hole transport layer with facile molecular doping for highly efficient perovskite solar cells
2023, Journal of Power Sources
Citation Excerpt :
Thus, the energy level and the charge extraction/transportation ability of the CTL have significant impacts on the PV parameters of the PSC device including their stability [19–21]. In this perspective, various studies on CTL-engineering have been conducted, and the dopant design for tuning their energy levels and thus enhancing their charge extraction/transportation properties is one of the representative works [22–25]. Especially, in hole transport materials (HTMs) of PSCs, where inorganic p-type semiconductors such as NiOx, CuOx, MoOx, and VOx are used, dopants such as transition metals [26–29], alkali metals [30–33], rare earth metals [34], and carbon-based materials [35] have been applied to improve their electrical and optical properties along with the film morphology.
Energy level and the charge extraction/transportation ability of the hole transport layer (HTL) have significant impacts on the photovoltaic (PV) parameters of the perovskite solar cell (PSC) devices. A doping process has been one of the representative works to manage these characteristics, but the solution-blend doping, widely applied to the organic semiconductor HTL, has shown limited processability. In this work, we design a facile interfacial doping process for poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) HTL in p-i-n structure PSC device. This approach provides superior optical and electrical properties to the PTAA layer, even with better processability, and its proper hydrophobicity is beneficial to forming pinhole-free perovskite even with superior crystallinity and reduced trap density. Moreover, the dipole layer localized at the interface with the perovskite enhance the built-in potential of device, improving its carrier transportation. As a result, this approach largely enhances the efficiency of the p-i-n PSC device from 18.06% (blend-doping) to 20.67% with superior stability preserving 94% of its initial efficiency after 500 h under ambient air.

View all citing articles on Scopus

Ali Asgher Syed is currently a postdoctoral fellow at Institute of Energy research, Jiangsu University, China. He received his Ph.D. degree from Hong Kong Baptist University, Hong Kong in 2018. He had worked as senior research assistant in department of Physics, Hong Kong Baptist university (2018–2019). His main research interest includes highly efficient planar perovskite solar cells (PSC), charge transportation and recombination dynamics in PSC.

Cheng Chen received her Ph.D degree in 2014 from the State Key Laboratory of Fine Chemicals at Dalian University of Technology (DUT). Then she worked as a post-doc in KTH Royal Institute of Technology, hosted by Prof. Lars Kloo. In June 2017, she joined Jiangsu University as a full professor. Her research is mainly focused on new functional materials for dye-sensitized solar cells, perovskite solar cells and organic solar cells.

Cheng Wu received his Bachelor's degree from Chaohu University in 2018. Now he is a master student supervised by Prof. Cheng Chen at Jiangsu University. His current research interest mainly focuses on developing low-cost and highly efficient organic interlayer for perovskite solar cells.

Li Tao received his Bachelor's degree from Changzhou Insititute of Technology in 2017. Now he is a Master student supervised by Prof. Hongfei Lu at Jiangsu University of Science and Technology. His current research interest mainly focuses on developing low-cost and highly efficient organic interlayer for perovskite solar cells.

Xingdong Ding received his Bachelor's degree from Chuzhou University in 2017. Now he is a master student supervised by Prof. Ming Cheng at Jiangsu University. His current research interest mainly focuses on developing low-cost and highly efficient hole transport materials for perovskite solar cells.

Yawei Miao received his MS in 2019 from the school of material science and engineering at Qingdao University. Currently, he is pursuing his PhD in the Cheng laboratory at Jiangsu University. His research focuses on perovskite solar cells, including surface defect passivation and device interlayer engineering.

Gongqiang Li is currently a full professor at Nanjing Tech University. Dr. Li earned his bachelor degree in Chemistry from Wuhan University, and he then completed his Ph. D. from Shanghai Institute of Organic Chemistry, CAS. Then he was awarded Alexander von Humboldt Research Fellowship in Germany. Dr. Li's research group is currently working on organic solar cells and transporting materials for perovskite solar cells with high performance. Dr. Li has authored/co-authored more than 30 peer-reviewed articles with 1100 citations.

Ming Cheng received his PhD degree from Dalian University of Technology in 2014. After that, he went to KTH Royal Institute of Technology in Sweden for postdoctoral research under the host of Prof. Licheng Sun. In June 2017, he joined Jiangsu University as a full professor. Currently, his research interests mainly focus on perovskite solar cells.

Liming Ding got his PhD from University of Science and Technology of China (was a joint student at Changchun Institute of Applied Chemistry, CAS). He started his research on OSCs and PLEDs in Olle Inganäs Lab in 1998. Later on, he worked with Frank Karasz and Tom Russell at PSE, UMASS Amherst. He joined Konarka as a Senior Scientist in 2008. In 2010, he joined National Center for Nanoscience and Technology as a Full Professor. His current research includes perovskite solar cells, organic solar cells and photodetectors.

View full text

Dual effective dopant based hole transport layer for stable and efficient perovskite solar cells

Highlights

Abstract

Graphical abstract

Section snippets

CRediT authorship contribution statement

Declaration of competing interest

Acknowledgements

Sci. Bull.

Sci. Bull.

Sci. Bull.

Mater. Today

Sci. Bull.

Joule

Inside Chem.

Joule

Nat. Photon.

Adv. Energy Mater.

Nat. Energy

Science

Nature

Adv. Energy Mater.

Adv. Energy Mater.

Nat. Rev. Mater.

Science

Science

Adv. Sci.