[20p-P7-1~20] 9.2 Nanowires and Nanoparticles

[20p-P7-15] Si-based nano-flakes: Optical and photocatalytic properties

〇Hiroshi Itahara¹, Xiaoyong Wu², Yoshiki Yamazaki², Haruo Imagawa¹, Shu Yin², Kazunobu Kojima², Shigefusa Chichibu², Tsugio Sato² (1.Toyota CRDL, 2.Tohoku Univ.)

Keywords:silicon,silicide,photocatalyst

We have developed a nanocomposite comprised of Si-based nanoflakes and nickel (and nickel silicide) particles by using a solid-state exfoliation method using layered CaSi₂. The nanoflaks were formed by extracting Ca from CaSi₂ and thus their compositions were close to Si. The nanocomposite showed the direct optical band gap of ~ 1.8 eV where a bulk silicon shows the indirect optical band gap of ~ 1.1 eV. Furthermore, the synthesized nanocomposite exhibited a photocatalytic property that a bulk silicon never shows.