Photonic materials utilizing naturally occurring nanostructures

Hayato Kamioka, Hidenori Hiramatsu, Katsuro Hayashi, Masahiro Hirano, Hideo Hosono

Research output: Contribution to journalArticlepeer-review

9 Citations (Scopus)


We report distinct optical/electrical properties inherent to build-in nanostructures in transparent oxide based materials, oxychalcogenides LaCuOS and LaCuOSe having naturally formed multi-quantum well structures and 12CaO·7Al2 O3 (C12A7) with a unique nanoporous structure. LaCuOSe doped with Mg ions exhibit degenerative p-type conduction presumable due to "modulation doping mechanism" with a high mobility of 4.0 cm2 V-1 s-1 even at high hole concentration (∼2×1020 cm-3). The room temperature exciton, having a large binding energy (∼50 meV) due to the confinement effect of carriers in the CuS or CuSe layer, induces a large optical nonlinearity at room temperature (RT) (χ(3) = 2-4×10-9 esu) near the absorption band. The H- ion entrapped in nanosize cages in C12A7 lattice causes an persistent conversion at RT from an electric insulator (<10-10 S cm-1) to a semiconductor (0.3-100 S cm-1) by capturing electrons photo-ionized from H- ions in the cages. This is a first electronic conductor based on main group light metal oxides.

Original languageEnglish
Pages (from-to)141-147
Number of pages7
JournalJournal of Photochemistry and Photobiology A: Chemistry
Issue number1-3
Publication statusPublished - Aug 12 2004
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Chemical Engineering(all)
  • Physics and Astronomy(all)


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