Sanggyun Kim

Advisor: Prof. Juan-Pablo Correa-Baena

will propose a doctoral thesis entitled,

Organic Electronic Interlayers for Long-Term Stability of Halide Perovskite Solar Cells

On

Wednesday, Feb. 7, 2024

10am - 12pm.
MRDC Room 3515

Committee:

Prof. Juan-Pablo Correa-Baena – School of Materials Science and Engineering (advisor)

Prof. John R. Reynolds – School of Chemistry and Biochemistry/School of Materials Science and Engineering

Prof. Ajeet Rohatgi – School of Electrical and Computer Engineering

Prof. Jason D. Azoulay – School of Chemistry and Biochemistry/School of Materials Science and Engineering

Prof. Anju Toor – School of Materials Science and Engineering

Abstract

Organic-inorganic hybrid perovskite solar cells (PSCs) have dramatically improved 

in power conversion efficiency (PCE) since their advent, reaching up to 26.1%. 

While substantial progress has been made in enhancing PSC efficiency, stability 

remains to be one of the critical challenges to their commercialization. Specifically, the

charge transport materials (CTMs) and their interfaces with the perovskite absorber layer

are widely acknowledged as the primary impediment to achieving long-term stability. 

This limitation stems from the susceptibility of these interlayers to degradations induced 

by various factors, including cracking, moisture ingress, ion migration, and chemical 

reactions. These degradation processes are responsible for the structural and electronic 

integrity of PSCs, which motivates in-depth understanding of interlayer degradation 

mechanisms. This thesis aims to elucidate the multifaceted role of interlayers in enhancing 

PSC stability, with a specific emphasis on integrating novel organic CTMs that include 

conjugated polymers (CPs) and small molecules. Here, I first focus on a comprehensive

examination of 1,4-(2-thienyl)-2,5-dialkoxyphenylene based CPs as hole transport layer

in PSC. Subsequently, the study expands to explore isoindigo based CPs and naphthalene 

diimide based molecules as plausible electron transport layers in PSC. The interlayer studies

entail multidisciplinary methodology, involving structural and optoelectronic analyses 

alongside device-level studies. Lastly, charge carrier dynamics between different organic 

CTMs and perovskite layer as function of aging will be studied through time-resolved 

spectroscopy. These comprehensive works not only validate the profound impacts of 

organic CTMs on PSC stability but also establish their technological significance at the 

interfacial level. In doing so, I aim to contribute to the broader understanding of PSCs 

and pave the way for the development of more stable photovoltaic technologies.