Multiphoton absorption (MPA) materials are widely used in fields such as data storage, optical limiting, micromachining, up-conversion lasers and biological imaging. However, MPA reported so far mainly concentrates in the two/three-photon absorption processes, and there is an extreme lack of research on the high-order MPA (especially seven-photon absorption) processes.
Recently, Prof. Chen Daqin's research group of FNU, together with Chen Xueyuan, researcher of Fujian Institute of Research on the Structure of Matter (FJIRSM), Chinese Academy of Sciences (CAS), prepared Cs2Na0.4Ag0.6In1-xBixCl6 double perovskites with superior stability and nearly 100% luminescence efficiency by aliovalent substitution. Density functional theory calculations verify the effect of Na/Bi alloying on optical absorption of double perovskites, which can be pumped by a femtosecond laser in a wide spectral range (800–2600 nm), and nonlinear multi-photon (2–7) absorption in lead-free double perovskites was observed for the first time.
The work, titled “Seven-photon absorption from Na+/Bi3+-alloyed Cs2AgInCl6 perovskites”, was published in Materials Horizons. The first organization of the paper is FNU, with Jin Shilin, a graduate student of College of Physics and Energy, and Li Renfu, an engineer of FJIRSM, as the co-first authors, and Researcher Chen Xueyuan, Prof. Chen Daqin and Prof. Wu Tianmin of FNU, as the co-corresponding authors. The work was supported by the National Natural Science Foundation of China and the Key Natural Science Foundation of Fujian Province.
Paper link: https://pubs.rsc.org/en/content/articlelanding/2023/mh/d2mh01396g
(Translated by Chen Xinhao/ Reviewed by Xie Xiujuan)