MRS Meetings and Events


EN05.10.29 2023 MRS Fall Meeting

Enhancing Interfacial Properties via Ionic Exchange for the Highly Efficient Sn-Pb Mixed Perovskite Based Solar Cells

When and Where

Nov 29, 2023
8:00pm - 10:00pm

Hynes, Level 1, Hall A



Sangheon Lee1,Changyong Kim1,Hyemin Lee1,Seok Beom Kang1,Joo woong Yoon1,Sang Won Lee1,Dong Hoe Kim1

Korea University1


Sangheon Lee1,Changyong Kim1,Hyemin Lee1,Seok Beom Kang1,Joo woong Yoon1,Sang Won Lee1,Dong Hoe Kim1

Korea University1
Sn-Pb mixed perovskite is considered as an ideal light absorber not only for single-junction solar cells, but also for bottom cells of muti-junction solar cells due to its narrow-band gap feature. The p-orbital hybridization of Sn<sup>2+</sup> and Pb<sup>2+ </sup>causes an upward shift of the valence band maximum (VBM) and conduction band minimum (CBM) in addition to the bandgap reduction. This results in the highest occupied molecular orbital level of poly[3,4-ethylenedioxythiophene]:poly[styrene sulfonate] (PEDOT:PSS) having an ideal band alignment with the VBM of Sn-Pb mixed perovskite. Therefore, the PEDOT:PSS is the most widely used hole transport layer (HTL) in p-i-n structured Sn-Pb mixed perovskite solar cells (PSCs).<br/><br/>However, PEDOT:PSS showed several critical drawbacks that affected the device performance such as their acidic condition, inferior molecular structure, and nonideal absorption property. Among them, the inappropriate molecular structure composed of hydrophilic PEDOT molecule and hydrophobic PSS molecule does not form a uniform and ideal micro structured surface when it has been coated. Therefore, it has been induced undesirable interface like voids between PEDOT:PSS and perovskite. Various studies have been conducted to obtain better interfacial properties with respect to the perovskite precursor, like adding additives. However, the origin of the undesirable interface was due to the structural limit of the PEDOT:PSS molecule. Therefore, fundamental research is needed to address these issues from the perspective of the PEDOT:PSS surface.<br/><br/>This study introduces an effective ionic exchange for PEDOT:PSS surface modification to drastically enhance the interfacial properties between PEDOT:PSS and perovskite. The surface modified PEDOT:PSS by ionic exchange brought the conformal interfacial contact and enhanced charge extraction confirmed via time-resolved photoluminescence (TRPL) analysis. As a result, we achieved more than 20% efficiency of p-i-n structured Sn-Pb mixed PSCs. The mechanism of ionic exchange also had been elucidated through various surface analysis and density functional theory (DFT) calculations. In addition, we confirmed that this ionic exchange was also effective for tandem devices. In conclusion, we fabricated all-perovskite tandem solar cells with an approaching 24% efficiency through this ionic exchange



Symposium Organizers

Marina Leite, University of California, Davis
Lina Quan, Virginia Institute of Technology
Samuel Stranks, University of Cambridge
Ni Zhao, Chinese University of Hong Kong

Symposium Support

Enli Technology Co., LTD

APL Energy | AIP Publishing

Session Chairs

So Min Park
Lina Quan

In this Session

Interstitial Defect Relaxation DFT Study of Lead Halide Perovskites

Water-Assisted Morphology and Crystal Engineering of Hybrid Organic-Inorganic Halide Perovskite: Implications for Optoelectronic Properties

Self-Leveling Inks for Engineering Large Area Uniformity in High-Performance Flexography-Printed Perovskite Solar Cells

Towards Highly Efficient Fully Evaporated Perovskite/Si Tandem Solar Cells

The Outstanding Role of Dielectricity in Hybrid Solar Cell Absorbers

Controlling The Crystallization of Pure Bromide Quasi-2-Dimensional Perovskite Crystals for High Efficiency Pure-Blue Light-Emitting Diodes

Compositional Engineering of Single-Crystal Perovskite for Highly Efficient Photovoltaics

Atomistic Origin of Transparent Absorption Spectra of Halide Perovskites

Exploring a Novel Family of Conjugated Polymers for High Efficiency and Thermally Stable Perovskite Solar Cells

Charge Transfer Doping of Ruddlesden–Popper Metal–Halide Perovskites via Bulk Incorporation of Organic Molecular Dopants

View More »

Publishing Alliance

MRS publishes with Springer Nature