Tailored circular Bragg phenomena in TiO2 sculptured thin films through post-deposition processing

Sean M. Pursel; Mark W. Horn; Akhlesh Lakhtakia

doi:10.1117/12.732413

11 September 2007 Tailored circular Bragg phenomena in TiO₂ sculptured thin films through post-deposition processing

Sean M. Pursel, Mark W. Horn, Akhlesh Lakhtakia

Proceedings Volume 6645, Nanoengineering: Fabrication, Properties, Optics, and Devices IV; 66450X (2007) https://doi.org/10.1117/12.732413
Event: NanoScience + Engineering, 2007, San Diego, California, United States

Abstract

Chiral sculptured thin films (STFs) of TiO₂ deposited by the serial bi-deposition method can be modified post-deposition to tailor the circular Bragg phenomenon which occurs due to their periodic helical morphology. This post-deposition tailoring is accomplished through annealing and/or wet chemical etching. Annealing of the chiral STF in spectral-hole-filters (SHFs) transforms the material structure from non-crystalline to an anatase structure which is more stable and provides better optical performance. The transformation causes a blue-shift of the circular Bragg phenomenon (CBP) which is quantified and correlated with material properties. Further annealing causes a significant change in morphology, which resembles a "string of pearls", and may be the cause of a loss of transmission. Wet chemical etching is also capable of blue-shifting the Bragg regime of a non-crystalline SHF, while having very little effect on a crystalline SHF. The spectral shift of the Bragg regime is limited by the ability of the nanowires, of which the STFs are composed, to remain attached to the substrate. Wet chemical etching and annealing can be used in combination to allow more control of post-deposition processing.

Citation Download Citation

Sean M. Pursel, Mark W. Horn, and Akhlesh Lakhtakia "Tailored circular Bragg phenomena in TiO₂ sculptured thin films through post-deposition processing", Proc. SPIE 6645, Nanoengineering: Fabrication, Properties, Optics, and Devices IV, 66450X (11 September 2007); https://doi.org/10.1117/12.732413

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members: $17.00

Non-members: $21.00 ADD TO CART

PROCEEDINGS
8 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY

GET CITATION

RIGHTS & PERMISSIONS

Get copyright permission Get copyright permission on Copyright Marketplace

KEYWORDS

Annealing

Nanowires

Etching

Crystals

Transmittance

Wet etching

Bromine

Show All Keywords

Keywords/Phrases

Search In:

Publication Years