Characteristics in 1D & 2D chiral perovskite single crystals and thin films

Chia-Hsiang Chuang^1*

¹Department of Physics, National Taiwan Normal University, Taipei, Taiwan

* Presenter:Chia-Hsiang Chuang, email:vernier0914@gmail.com

Low-dimensional perovskites have recently attracted considerable attention due to their unique optical and electronic properties. Chiral low-dimensional perovskites exhibit circular dichroism (CD) signals that are strongly dependent on the dimensionality and molecular arrangement of the perovskite layers. In this work, we investigate the differences between one-dimensional (1D) and two-dimensional (2D) chiral perovskites to understand how dimensionality influences their optical activity and device performance.
This study first compares the CD spectra, photoluminescence (PL), and LED characteristics of 1D and 2D perovskite films. In this research, CD spectrum is a crucial indicator, more people effort to promote g-factor (or g-abs value). This research aims to compare g-abs between 1D and 2D and determine which is better.
While optical characterization can identify which perovskite exhibits stronger chiroptical properties, it does not reveal the corresponding electrical behavior. To address this, both types of perovskites were integrated into LED to evaluate their electrical performance, particularly their external quantum efficiency (EQE). It is observed that thicker perovskite films tend to produce stronger CD signals but suffer from reduced electrical conductivity. Conversely, thinner films facilitate better charged transport but exhibit weaker CD intensity.
This trade-off highlights the importance of optimizing the film thickness to balance optical and electrical properties. The next stage of this research focuses on identifying the optimal film thickness that simultaneously maintains strong CD response and high EQE in perovskite-based LEDs. This study provides valuable insight into the relationship between dimensionality, chiroptical behavior, and device efficiency, contributing to the development of high-performance chiral optoelectronic materials.

Keywords: perovskite, LED, chiral