Wednesday 05 March 2025
Researchers have made a significant breakthrough in the development of lead-free halide perovskites, a class of materials that have shown great promise for optoelectronic applications such as solar cells and light-emitting diodes. In a recent study, scientists from the Indian Institute of Science Education and Research Kolkata investigated the properties of Cs2TeCl6, a vacancy-ordered halide double perovskite, under high pressure.
The researchers used a range of techniques, including synchrotron X-ray diffraction and Raman spectroscopy, to probe the structural and optical changes in Cs2TeCl6 as it was subjected to increasing pressures up to 30.5 gigapascals (GPa). They found that the material undergoes a series of phase transitions, switching between cubic and monoclinic structures, which has important implications for its electronic properties.
One of the most significant findings is the enhancement of photoluminescence (PL) intensity in Cs2TeCl6 under pressure. The PL signal, which arises from the recombination of electrons and holes, increases by a factor of six at 1.2 GPa compared to ambient conditions. This increase is attributed to the distortion of TeCl6 octahedra, which leads to an enhancement of electron-phonon coupling.
The researchers also observed a blue shift in the PL peak position with increasing pressure, indicating that the energy level of the self-trapped excitonic state increases. Furthermore, they found that the full-width half maximum (FWHM) of the PL spectrum decreases under compression, suggesting a reduction in the strength of electron-phonon coupling.
The results have important implications for the development of lead-free halide perovskites for optoelectronic applications. The ability to enhance PL intensity through pressure tuning could be used to optimize the performance of devices such as solar cells and light-emitting diodes. Additionally, the study provides valuable insights into the structural and optical properties of Cs2TeCl6 under high pressure, which can inform the design of new materials with improved optoelectronic characteristics.
The researchers used a combination of experimental techniques and theoretical modeling to investigate the properties of Cs2TeCl6 under high pressure. They employed synchrotron X-ray diffraction to probe the structural changes in the material as it was subjected to increasing pressures, and Raman spectroscopy to study the optical properties.
Cite this article: “High-Pressure Tuning of Optoelectronic Properties in Lead-Free Halide Perovskites”, The Science Archive, 2025.
Lead-Free Halide Perovskites, Cs2Tecl6, High Pressure, Phase Transitions, Photoluminescence, Electron-Phonon Coupling, Solar Cells, Light-Emitting Diodes, Optoelectronic Applications, Vacancy-
