Molecular Layer Deposition”ORGANIC ALD”

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Overview

MLD: Technology and principle

Opportunities and challenges

Applications

Summary

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MLD: Technology and principle (1/2)

In short: ALD, but with molecules

(Generally) self-limiting reactions

Solution-based and gaseous phase techniques

Hybrid technology with ALD to create ALD-MLD films

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MLD: Technology and principle (2/2)

Basic cycle:

Fill chamber with inert gas to purge atmosphere of foreign particles

Replace with desired gaseous reactant

Substrate surface will react with gaseous reactant until all of surface is covered

One layer of desired material is deposited

Repeat from the top, changing reactants for different materials

[1] p.534

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Opportunities and challenges

Organic component increases flexibility, decreases density and can reduce cost

Structural benefits from hollow/cavernous structures for catalysts (after removing organic constituent)

Wide range of possibilities (metal + organic molecule)

Issues with even growth per cycle, due to molecule geometry

[1]: p.539

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Applications

Widest research area so far: metalcones (metal+alcohol)

Al, Zn, Zr, Hf, Mg, Sn, In, Ti, V, Mn are all viable metals for metalcones

Organic component: Ethylene glycol, Glycerol, Hydroquinone

Zincones can be used for flexible transparent conductive displays

Titanicone structures can be utilized in solar cells

Porous films can act as catalysts or sensors (Sn, In, V, Mn)

MLD also used to coat fine particles (passive or active)

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Summary

MLD: In essence ALD, but with organic molecules

Self-limiting surface reactions

Stackable with ALD for organic-inorganic composite films

Main benefits in flexible and lightweight structures

Tuneable thin-film structural composition

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Thank You!

[2]

[4]

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Sources

[1]: Lee, B.H., Yoon, B., Abdulagatov, A.I., Hall, R.A., George, S.M. Growth and properties of hybrid organic-inorganic metalcone films using molecular layer deposition techniques. (2013) Advanced Functional Materials, 23 (5), pp. 532-546. http://www.scopus.com/inward/record.url?eid=2-s2.0-84873356095&partnerID=40&md5=dc679dabf8c7895d0e39926b603cd207

[2]: http://www.hanyang.ac.kr/code_html/H3HNCK886/introEng/research/img/2.jpg

[3]: King, D.M, Liang, X., Weimer, A.W. Functionalization of fine particles using atomic and molecular layer deposition. (2011) Powder Technology, 221 (2012), pp.13-25.

[4]: http://3.bp.blogspot.com/_tCh0LGvTCqE/THyN-E7cAOI/AAAAAAAAALY/kyT9eUPSSZg/s1600/MLD.JPG