We reveal unusual electronic and structural changes of nano-crystalline CsPbBr3 at different temperatures. Using high-resolution spectroscopic ellipsometry, high-resolution transmission electron microscopy, terahertz spectroscopy and supported by first-principles calculations, we find that a new dual structural phase is observed due to an effect of the material’s nano-crystalline nature. We also develop a method of determining the phase transitions within the material through the identification of optical transitions within the electronic structure and the comparison of experimental data and theoretical models. Our result shows the importance of the interplay between charge and lattice in determining structural and electronic properties of nano-crystalline materials.
- T. J. Whitcher
- L. C. Gomes
- A. Rusydi
