Revolutionary advancements in semiconductor technology have emerged with the creation of 2D halide perovskites, which hold incredible promise for applications in solar cells and light-emitting diodes.
A team of scientists led by Assoc Prof Nripan Mathews from NTU‘s School of Materials Science and Engineering has successfully synthesized four groundbreaking types of these perovskites. The lead author, Dr. Ayan Zhumekenov, a dedicated research fellow, pioneered a unique method by incorporating dimethyl carbonate—a non-toxic solvent—into methylammonium-based perovskite crystals.
Through the examination of the new crystal structures, the researchers found that they could modify the band gap by varying the proportions of methylammonium and dimethyl carbonate within the materials. The band gap, which is responsible for the material’s color, represents the energy needed for an electron to escape its bound state and achieve conductivity.
The capability to manipulate the width of the band gap is crucial for the diverse uses of perovskites. The newly developed 2D halide perovskites also demonstrate a dynamic “switchable” property.
The researchers discovered that one of the perovskites can alternate between two color states, transitioning from orange to red when subjected to a temperature of 80 degrees Celsius and returning to its initial color upon cooling back to room temperature.
The scientists showed that this color-changing reaction could be repeated for up to 25 cycles. This thermochromic switching phenomenon presents opportunities for applications such as smart coatings and heat-sensitive inks that alter color at varying temperatures.
The researchers are optimistic that their breakthrough will lead to technological advancements involving 2D halide perovskites in optoelectronics and other fields.
Journal reference:
- Ayan A. Zhumekenov, Yongxin Li, Yifan Zhou, Natalia Yantara, Anil Kanwat, Benny Febriansyah, Darrell Jun Jie Tay, Hesham R. Abuzeid, Yeow Boon Tay, Emha Bayu Miftahullatif, Kedar Hippalgaonkar, Sumod A. Pullarkat, Jun Yin, Nripan Mathews. Solvent-Templated Methylammonium-Based Ruddlesden–Popper Perovskites with Short Interlayer Distances. Journal of the American Chemical Society, 2024; DOI: 10.1021/jacs.3c12891
