| Budget Amount *help |
¥4,240,000 (Direct Cost: ¥3,700,000、Indirect Cost: ¥540,000)
Fiscal Year 2007: ¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000)
Fiscal Year 2006: ¥1,900,000 (Direct Cost: ¥1,900,000)
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| Research Abstract |
A main purpose of this study is to develop a single-electron optical memory. Key elements for this purpose are organic molecules for Coulomb islands multi-layer structure for device configuration and single-electron tunneling as a quantum phenomenon. In the case of conventional single-electron memories, transportation of electrons is controlled by external electric field. Meanwhile, electron can be transported by light irradiation in our device. For this purpose, photochromic molecules are employed for Coulomb islands in the insulator/molecule/insulator multilayers. HOMO-LUMO levels of the molecule can be changed through the photo-isomerization, which can be reconstituted by another light irradiation with different wavelength. In our study, we employed a porphyrin derivative for a molecule, SiO2 and CaF2 thin films for tunneling barriers, highly-doped Si substrate and Au thin film for electrodes, respectively. We found a periodic staircase in I-V curve and its shift caused by light irradiation. Importantly, the shift in I-V curves was reversible, i.e. the shifted I-V curve returned to the original one after the These results give evidences that the porphyrin molecule can act as Coulomb islands for electron tunneling and our device configuration have a potential of single-electron optical memory.
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