1992 Fiscal Year Final Research Report Summary
LUMINESCENCE FROM SOLID SURFACES BASED ON ELECTRON TRANSFER AT INTERFACES
Project/Area Number |
02455011
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Research Category |
Grant-in-Aid for General Scientific Research (B)
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Allocation Type | Single-year Grants |
Research Field |
広領域
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Research Institution | TOKYO INSTITUTE OF TECHNOLOGY |
Principal Investigator |
SAKATA Tadayoshi TOKYO INSTITUTE OF TECHNOLOGY, DEPARTMENT OF ELECTRONIC CHEMISTRY, PROFESSOR, 大学院総合理工学研究科, 教授 (40013510)
|
Co-Investigator(Kenkyū-buntansha) |
KUDO Akihiko TOKYO INSTITUTE OF TECHNOLOGY, DEPARTMENT OF ELECTRONIC CHEMISTRY, ASSISTANT RES, 大学院総合理工学研究科, 助手 (60221222)
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Project Period (FY) |
1990 – 1992
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Keywords | Al oxide electrode / electroluminescence mechanism / luminescence from particulate semiconductors / time resolved electroluminescence / Excitation by electron collision / electron transfer at electrode interface / 電子衝突励起 / 界面電子移動 |
Research Abstract |
In order to elucidate the relation between the electroluminescence and the electron transfer, the electroluminescence from porous Al oxides in the pores of which luminescent particulate semiconductors are supported was studied. When a small voltage of 10 V was applied on the Al oxide electrode, clear electroluminescences were observed. Those electroluminescence spectra agreed well with the photoluminescence spectra of the supported semiconductor particles such as CdS and ZnS.This result demonstrates clearly that the particulate semiconductors on the porous Al_2O_3 surface are excited to generate luminescence. In order to clarify the excitation mechanism, rectangular pulsed voltage of 100Hz was applied to the Al_2O_3 electrode. From the time resolved measurement of the electroluminescence, it was found that the luminescence intensity was increased with the cathodic polarization of the electrode, while no luminescence was observed by the anodic polarization. It was also found that the time course of the electroluminescence intensity agreed well with that of the electric current. This new result was explained well by an solid state electronic model in which Al_2O_3 is considered as a n-type semiconductor. In this model the electroluminescence of Al_2O_3, whose surface is supported by particulate Cds and ZnS, is explained by the following processes : 1) Electrons are injected from Al into the conduction band of al_2O_3 at catodic polarization. 2) These injected electrons get energy by being accelerated in the strong electric field in tha Al_2O_3 layr. 3)These energetic electrons collide with the particulate semiconductors supported on the Al_2O_3 surface. The particulate semiconductors are excited by the collision to generate luminescence.
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Research Products
(18 results)