From the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS), Dr. A research team led by Yang Bing developed and investigated cadmium (Cd)-based perovskite single crystals with long-lasting and high quantum yields. afterglow dynamics mechanism.

Postluminescent materials have the ability to store multiple radiations such as visible photons, ultraviolet rays and X-rays. They are widely used in displays, bioimaging, anti-fraud technology, and data storage.

However, conventional purely inorganic phosphors such as oxide, sulfide and nitride-based backlight materials have high lattice energies and typically require high temperature processing (>1000 °C), resulting in significant energy consumption and safety. production and preparation risks.

Using a single solution-treated perovskite crystal of CsCdCl₃ As an afterglow matrix, the researchers proposed a luminescence strategy based on energy transfer from triple self-closing excitons (STE) to the Mn acceptor.⁺ due to Mn doping^2+. They developed a highly efficient, ultra-long final glow phosphor with anti-thermal quenching, which can simultaneously achieve a high luminescence quantum yield (81.5%) and an ultra-long post-flare time (150 seconds).

They also provided clear evidence for the luminescence mechanism through in-depth studies of carrier dynamics and density functional theory (DFT) calculations. The structure of CsCdCl ₃ mn²⁺ have [CdCl₆]⁴ – an octahedron with plane symmetry (symmetry C _3v) and angular symmetry (symmetry D_{3-dimensional}) can create non-equivalent Cl vacancies and lead to trap states with a wide energy distribution.

“We found that these trap states can store charge carriers and slowly release them into the emission center ([MnCl₆]⁴ – octahedron), causing afterglow emission with anti-thermal quenching effect,” said Dr Yang.