Research

Our mission is to improve long-term stability of emerging nano-energy materials and their corresponding devices from both chemical and mechanical perspectives. We are conducting synthesis research on two-dimensional hybrid organic-inorganic perovskites (2D HOIPs) from the perspective of chemical composition and structural design, aiming to optimize their physical and photochemical properties. In particular, we are focusing on comprehensively understanding the structural factors that influence the mechanical/chemical durability and optoelectronic properties of these materials, and applying that understanding to enhance their performance. We also employ atomic force microscopy (AFM) to precisely analyze changes in the physical and optoelectronic properties of 2D HOIPs under external stimuli commonly encountered during device operation—such as heat, electrical bias, and light. Based on these studies, we are actively pursuing research to improve the long-term stability and durability of materials and devices from both chemical and mechanical perspectives.

Currently active research includes:

1) Synthesis of two-dimensional hybrid organic-inorganic perovskites (2D HOIPs)

Two-dimensional hybrid organic–inorganic perovskites (2D HOIPs) have obtained considerable attention as next-generation electronic materials due to their exceptional promise for a broad spectrum of optoelectronic applications. Their intrinsic layered structure offers a highly versatile compositional landscape, allowing for fine-tuning of structural, electronic, and physical properties. Despite these advantages, the practical deployment of HOIP-based devices remains constrained by inherent chemical and mechanical instabilities, which limit their operational reliability and longevity. To overcome these limitations and enable the rational design of 2D HOIPs with tailored functionalities, it is essential to establish a comprehensive understanding of their structure–property relationships.

Representative papers: 

• ACS Applied Materials & Interfaces, 2021, 13 (27), 31642-31649; Advanced Science, 2023, 2303133; ACS Applied Nano Materials, 2023, 6 (10), 8214-8221; ACS Applied Materials & Interfaces, 2023, 15 (6), 7919-7927; ACS Nano, 2024, 18 (22), 14218–14230; Inorganic Chemistry, 2023, 62 (49), 20142-20152

2) 2D HOIPs-based devices for real-world applications: photocatalysis and optoelectronics

Translating materials research into real-world applications is essential for advancing technologies that directly enhance the quality of human life. Devices based on 2D HOIPs hold significant promise, particularly in the realms of photocatalysis and optoelectronics. These materials are being actively explored for solar-to-fuel conversion processes, including water splitting and CO2 reduction, offering pathways toward sustainable fuel production. In optoelectronic applications, 2D HOIPs are also being integrated into high-performance photodetectors, X-ray sensors, and light-emitting diodes. In our laboratory, we focus on improving both the energy conversion efficiency and long-term operational stability of these devices by systematically tuning the chemical composition and physical properties of 2D HOIPs.

Representative papers:

• Materials Horizons, 2024, 11, 5070-5080; Advanced Functional Materials, 2024, 2405717; Advanced Materials, 2025, 2413412; Advanced Energy Materials 2016, 6 (4), 1501754.

3) Advanced Atomic Force Microscopy

Atomic force microscopy (AFM) is a powerful and flexible tool that allows us to study materials in many different ways, with extremely high detail at the nanoscale. It can measure a wide range of material properties—such as how stiff, conductive, heat-responsive, light-sensitive, or semiconducting a material is. This helps us gain a deeper and more complete understanding of how materials work. Our lab has many types of AFM tools available (including AFM nanoindentation, Kelvin probe force microscopy (KPFM), Conductive AFM, Piezoelectric force microscpy (PFM) and Scanning  thermal microscopy (SThM)) and is also working on creating new AFM techniques. These efforts aim to improve what AFM can do and open new possibilities in nanoscale materials research.

Representative papers:

• Advanced Functional Materials, 2024, 2405717; ACS Applied Materials & Interfaces, 2021, 13 (27), 31642-31649; Advanced Science, 2023, 2303133; ACS Applied Nano Materials, 2023, 6 (10), 8214-8221; ACS Applied Materials & Interfaces, 2023, 15 (6), 7919-7927; InfoMat, 2024, e12561.