Grant-in-Aid for Scientific Research (A)
|Allocation Type||Single-year Grants|
Electronic materials/Electric materials
|Research Institution||Tokyo University of Agriculture and Technology|
KOSHIDA Nobuyoshi Tokyo Univ.of A&T,Prof., 工学部, 教授 (50143631)
KOYAMA Hideki Tokyo Univ.of A&T,Res.Assoc., 工学部, 助手 (40234918)
SUDA Yoshiyuki Tokyo Univ.of A&T,Assoc.Prof., 工学部, 助教授 (10226582)
|Project Period (FY)
1995 – 1997
Completed(Fiscal Year 1997)
|Budget Amount *help
¥34,100,000 (Direct Cost : ¥34,100,000)
Fiscal Year 1997 : ¥2,000,000 (Direct Cost : ¥2,000,000)
Fiscal Year 1996 : ¥9,900,000 (Direct Cost : ¥9,900,000)
Fiscal Year 1995 : ¥22,200,000 (Direct Cost : ¥22,200,000)
|Keywords||porous Si / Si nanocrystallites / quantum confinement / visible luminescence / Si light-emiting diode / Si photonic integration / bistable memory / ballistic electron emission / コールドカソード / シリコン発光素子|
To enhance the scientific and teachnological potential of silicon-based optoelectronics, the visible luminescence mechanism of porous silicon(PS)has been studied, including the device physics for monolithic photonic integrataion. Major results are summarized as fofllows.
1. Related issues to luminescence mechanism
(1) Bandgap widening occurs in luminescent PS,while its electronic and lattice structures maintain characteristic features of single-crystal silicon substrates.
(2) Definite correlation exists between bandgap and PL peak energy.
(3) Nanocrystal-related PL model is presented on a basis of spectroscopic analyzes of PL dynamics, polarization memory, and PL excitation process.
(4) PL spestra can be continuously tuned from red to blue simply by post-anodization photochemical etching without any further treatments like thermal oxidation.
(5) PL efficiency and stability can be improved by appropriate control of structure and surface termination of silicon nanocrystals in PS.
2. Fundamentals of integrated photonic devices
(1) By analyzes of electroluminescence (EL) mechanism in PS diodes, efficiency of 0.05% was obtained from diodes with a simple PS layr.
(2) Applicability of PS to optical cavity and three-dimensionally buried waveguide was demonstrated based on monolithic fabricataion technology.
(3) Availabilty of PS for optical logic gate was made clear by making use of non-linear optical effects.
(4) Some useful functions of PS as a confined system were observed in relation to the EL emission. Especially of importances are bistable memory effects and ballistic electron emission.