SITIS Topic Details |
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| Proposals Accepted: | |
| Program: | STTR |
| Topic Number: | AF10-BT19 (AirForce) |
| Title: | Organic & Hybrid Organic/Inorganic-Based Graded-Index/Layered Optical Coatings by Physical Vapor Deposition (PVD) | Research & Technical Areas: | Materials/Processes |
| Objective: | Fabrication of organic- and hybrid organic/inorganic-based graded-index/layered thin-films by physical vapor deposition techniques for use in AR coatings applications.
| Description: | Current metal oxides and metal sulfides used for graded index optical coatings tend to delaminate or develop stress cracks when deposited by magnetron sputtering onto the polymer surfaces of interest to the DoD. Delamination and stress cracks form in these coatings due to a mismatch in the coefficient of thermal expansion (CTE) between the coatings and the polymer substrates. Organic- and hybrid organic/inorganic-based graded-index thin-films are of interest as they will enable the deposition of adherent non-delaminating coatings onto polymer surfaces since the presence of the organic materials would result in little or no coating-substrate CTE mismatch. Hybrid organic/inorganic-based films would have the advantage of minimized CTE mismatch as well as higher refractive index, due to the presence of inorganic metal oxides and metal sulfides. Antireflective (AR) coatings require accurate thickness control, discrete materials deposition, and consistent thin-film uniformity. Vacuum deposition techniques such as pulsed laser deposition (PLD) can provide these requirements, however the structural and chemical integrity of organic-based materials are lost in these deposition processes. A modified PLD technique, matrix assisted pulsed laser evaporation (MAPLE) which involves dissolving an organic-based material in an appropriate solvent and freezing the solution solid to form an ablation target, unlike conventional PLD, preserves structural and chemical integrity. The solvent in the frozen solid matrix target evaporates when hit by laser pulses enabling the release of the organic material and subsequent deposition onto a desired substrate. This effort involves the design and fabrication of organic- and hybrid organic/inorganic-based graded-index/layered thin-films using MAPLE and combinations of MAPLE and other physical vapor deposition techniques such as resonant infrared-MAPLE (RIR-MAPLE), RIR-PLD, PLD, and magnetron sputtering, for use in AR coatings applications. Appropriate processing parameters and optical coatings designs derived from mathematical modeling (MM) and spectroscopic ellipsometry (SE), for fabrication of envrionmentally durable adherent coatings (according to MIL-C-48497A), with controlled thickness, minimal stress, minimal water content and controlled porosity, should be identified and result in a repeatable and controllable thin-film fabrication process.
| PHASE I: Select organic- and hybrid/organic-based materials, processing parameters and optical coatings designs derived from MM and SE, to demonstrate a environmentally durable adherent AR coating (400 nm - 750 nm passband; R<0.5%,T=99.5%) on a poly(carbonate) optical flat using one or more PVD techniques.
| PHASE II: Optimize physical vapor deposition techniques to prototype environmentally durable adherent organic- and hybrid organic/inorganic-based AR coatings (according to MIL-C-48497A) with a 400 nm-750 nm passband on curved poly(carbonate) and a reflectance of no greater than 0.5% (T=99.5% or greater) on curved poly(carbonate) ophthalmic blanks.
| PHASE III | DUAL USE COMMERCIALIZATION:
Military Application: Environmentally durable UV-protected organic- and hybrid organic/inorganic-based dielectric & AR coatings for military applications. Similar technologies also apply to more complex optical coatings.
Commercial Application: Environmentally durable UV-protected organic-based & hybrid organic/inorganic-based graded-index coatings could be optical coatings for commercial eye wear and energy efficient solar control coatings.
| References: |
1. Chrisey, D. B., Pique, A., McGill, R. A., Horwitz, J. S., Ringeisen, B. R., Bubb, D. M., Wu, P. K., “Laser Deposition of Polymer and Biomaterial Films”, Chemical Reviews 103 (2003) pp.553-576. 2. Edwards, G. S., Allen, S. J., Haglund, R. F., Nemanich, R. J., Redlich, B., Simon, J. D. and Yang, W.-C., “Applications of Free-Electron Lasers in the Biological and Material Sciences”, 81 (2005) pp.711-735. 3. Hunter, C. N., Check, M. H., Bultman, J. E., and Voevodin, A. A., “Development of matrix-assisted pulsed laser evaporation (MAPLE) for deposition of disperse films of carbon nanoparticles and gold/nanoparticle composite films”, Surface & Coatings Technology”, 203 (2008) pp. 300-306. 4. Karlsson, R. P. Shimshock, B. O. Seraphin, & J. C. Haygarth, “Optical properties of CVD-coated TiN, ZrN, & HfN”, Solar Energy Materials 7 (1983) pp. 401-411. 5. U.S. patent # 6,358,617, H. Ohsaki, Y. Tachibana, T. Oyama, H. Nishimura, & Y. Katayama, “Light absorptive antireflection & process for its production”, Issued March 19, 2002. 6. F. Samson, "Ophthalmic lens coatings", Surface and Coatings Technology 81(1996) pp.79-86. 7. MIL-C-48497A, COATING, SINGLE OR MULTILAYER, INTERFERENCE: DURABILITY REQUIREMENTS FOR (8 SEP 1980). www.everyspec.com/MIL-SPECS/MIL+SPECS+(MIL-C)/MIL-C-48497A_6070 8. E. Colton & S. Pellicori, "Coating ophthalmic lenses", Coating Materials News Vol. 7 Issue 4 (1997). 9. D. Sanchez & S. Pellicori, "Tutorial on testing and analysis of optical coatings", Coatings Material News Vol. 17 Issue 4 (2007). |
| Keywords: | physical vapor deposition, pulsed laser deposition, magnetron sputtering, matrix assisted pulsed laser evaporation, MAPLE, resonant infrared MAPLE (RIR-MAPLE) RIR-PLD, PLD, free electron lasers, dielectric coatings, absorbing anti-reflection coatings, high performance graded index optical interference notch filters and induced transmission filters |
Questions and Answers: |
Q: The solicitation specifically calls for the use of the MAPLE technique. Would the formation of organic/inorganic hybrid coatings by methods that did not specifically use MAPLE be appropriate? In other words, is the solicitation concerned with creating coatings with the desired performance enhancement (regardless of technique) or the development and commercialization of the MAPLE technique? Thank you in advance for your answers. |
A: This solicitation is concerned with the development and commercialization of the MAPLE technique either alone or in combination with other physical vapor deposition techniques (magnetron sputtering, PLD, RIR-PLD etc.) to create coatings with the desired performance |
Q: Q1: Are you specifically looking for the coating with organic material involved? Or you only concern about the thin film cracking issue caused by CTE mis-match on the polymer substrate. In other word, will you consider the approach using non-organic coating to fabricate the AR coating on polymer without CTE mismatch problem? |
A: Q1: The coating should be either organic- or a hybrid organic/inorganic based. |
As of midnight September 1, questions for solicitations SBIR 10.3 and STTR 10.B will no longer be accepted.
To read the solicitation for full proposal preparation and submission details click here. |