2006 Fiscal Year Final Research Report Summary
Light up-conversion mechanism of type-II dual sub-band superlattices
| Project/Area Number |
16560015
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Applied materials science/Crystal engineering
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| Research Institution | Hokkaido Institute of Technology |
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Principal Investigator |
IMAI Kazuaki Hokkaido Institute of Technology, Dept. Engineering, Professor, 工学部, 教授 (40001987)
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| Co-Investigator(Kenkyū-buntansha) |
KIMURA Nobuyuki Hokkaido Institute of Technology, Comprehensive Education Center, Professor, 総合教育研究部, 教授 (10204984)
SAWADA Takayuki Hokkaido Institute of Technology, Dept. Engineering, Professor, 工学部, 教授 (40113568)
SUZUKI Kazuhiko Hokkaido Institute of Technology, Dept. Engineering, Professor, 工学部, 教授 (30226500)
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| Project Period (FY) |
2004 – 2006
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| Keywords | II-VI compound semiconductor / superlattice / Type-II band structure / MBE growth |
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| Research Abstract |
The super-structured superlattice which consists of two kinds of single period superlattices with different quantum levels (dual sub-band (DSB) superlattice) shows two PL peaks. Under the excitation with the light with the mid-energy between the PL peaks, the DSB sample emits the peak at the upper energy side additionally to the lower side peak. We call this phenomena as light up-conversion effect. In this investigation, we study the mechanism in the type-II ZnSe-ZnTe superlattice.
The dependences of the energy and intensity of PL peaks on the excitation intensity on the samples with various structures were measured. Under the excitation with the light of Ar^+ laser (488 nm, 2.54 eV), all the samples have two PL peaks at both sides of the He-Ne line (633 nm, 1.96 eV). Under the excitation with He-Ne, all the samples indicate both peaks. The PL peak at the higher energy side is the up-converted light.
All the n values in the presentation of the excitation intensity dependence of the emission intensity (I_<em>〜I_<ex>^n) of the up-converted peaks were over 1.3. The sample with thin ZnSe parts (barriers in V.B.) has the value of n of 1.7. The energies of all the PL peaks indicate the blue shift with increasing the excitation intensity.
The mechanism of the up-conversion effect involves two steps process with the tunneling effect in V.B. and the recombination between the type-II levels.
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Research Products
(43 results)
