2016 Fiscal Year Annual Research Report
Design of narrow-band-gap h-BN and CNx light absorbers by layer edge-exposure and functionalization
| Project/Area Number |
16K21600
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| Research Institution | National Institute for Materials Science |
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Principal Investigator |
翁 群紅 国立研究開発法人物質・材料研究機構, 国際ナノアーキテクトニクス研究拠点, NIMSポスドク研究員 (70771210)
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| Project Period (FY) |
2016-04-01 – 2017-03-31
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| Keywords | boron nitride / functionalization / band gap / oxygen |
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| Outline of Annual Research Achievements |
Following the proposed methodology, we used both edge hydroxyl (-OH) functionalizaiton and plane interior oxygen doping for hexagonal boron nitride (h-BN) electronic structure turning. Theoretical investigations have predicted the feasibility of this methodology but it is still unclear to what extent the related properties can be alternated, because there are few significant experimental progresses and systematic theoretical investigations in this field. We have achieved the successful optical, electronic and magnetic properties of h-BN adjustment with the idea proposed in our project.
We have narrowed the optical band gap in h-BN nanosheets (from ~5.5 eV down to 2.1 eV) and confirmed the appearance of paramagnetism and photoluminescence in them after oxygen doping and functionalization. Thorough structural characterization has confirmed the presence of oxygen substitutions for nitrogen atoms within the BN in-plane lattices and the sp2 type hydroxylation at the plane edges. Combining with comprehensive theoretical simulations, we answered important questions that the electronic properties of h-BN monoatomic sheets are tunable and their band gap can be narrowed to ~1.7 eV through oxygen doping and/or functionalization.
These findings pave a new way for h-BN nanosheet optical, electronic and magnetic property engineering, and should shed lights on h-BN future applications in optical, electrical, and energy-related fields.
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