Ultrafast photo-induced metal–insulator transition in 1/4 filled organic crystal (EDO-TTF)2PF6

We report that the 1/4 filled A2B salt (EDO-TTF)2PF6 developed as a candidate for organic superconductor unexpectedly shows highly sensitive and ultra-fast photo-induced phase transition (PIPT) from insulator (I) to metal (M). We show the results of time resolved experiments performed on this crystal. A large reflectivity change in the near infrared region (1.2–2 eV), which occurs within 2 ps for weak excitation intensity, has been observed. We also observed coherent vibrations in the dynamical process of this transition.