PolyU Researchers Unlock the Potential of 2D Organic Perovskites in Electronics

A discovery by a research team led by Prof. LOH Kian Ping and Dr. Kathy LENG from The Hong Kong Polytechnic University (PolyU) has propelled the field of materials science into a new frontier. 

Recently published in the journal Science, their research unveils a breakthrough in synthesizing all-organic two-dimensional (2D) perovskites, marking a significant advancement in the realm of 2D materials.

Perovskites, named for their structural similarity to the mineral calcium titanate perovskite, are renowned for their properties applicable across various fields, including solar cells, lighting, and catalysis. Traditionally, perovskites have been explored as inorganic compounds, but Prof. Loh's team has shifted focus to the emerging class of all-organic perovskites, where organic molecules replace individual atoms in the A, B, and X constituents.

The team's innovative approach circumvents the challenges of synthesizing all-organic 3D perovskites by instead focusing on 2D layers, a strategy aimed at incorporating a broader range of organic ions. This pioneering method has led to the development of the "Choi-Loh-v phase" (CL-v) perovskites, named after Dr. Choi and Prof. Loh. These molecularly thin layers, stabilized by van der Waals forces, exhibit extraordinary properties and can be exfoliated into hexagonal flakes mere nanometers thick.

One of the most exciting aspects of this discovery is the solution-processibility of 2D organic perovskites, presenting promising opportunities for applications in 2D electronics. The research team's measurements on the dielectric constants of the CL-v phase have yielded impressive values, surpassing those of commonly used materials such as silicon dioxide and hexagonal boron nitride. This breakthrough paves the way for integrating CL-v phase as a dielectric layer in 2D electronic devices, enhancing their performance significantly.

Dr. Leng's contribution to the project involved successfully integrating 2D organic perovskites with 2D electronics, where the CL-v phase served as the top gate dielectric layer. By combining advanced fabrication techniques with the unique properties of CL-v phase, the team achieved superior control over the current flow in transistors, surpassing the capabilities of conventional dielectric layers.

Prof. Loh's research not only introduces a new class of all-organic perovskites but also demonstrates their potential for enhancing the performance of 2D electronic devices.