Title: Porous but Mechanically Robust All-Inorganic Antireflective Coatings Synthesized using Polymers of Intrinsic Microporosity

Abstract

Herein, we introduce polymer of intrinsic microporosity 1 (PIM-1) to design single-layer and multilayered all-inorganic antireflective coatings (ARCs) with excellent mechanical properties. Using PIM-1 as a template in sequential infiltration synthesis (SIS), we can fabricate highly uniform, mechanically stable conformal coatings of AlO_x with porosities of ~50% and a refractive index of 1.41 compared to 1.76 for nonporous AlO_x that is perfectly suited for substrates commonly used in high-end optical systems or touch screens (e.g., sapphire, conductive glass, bendable glass, etc.). We show that such films can be used as a single-layer ARC capable of reduction of the Fresnel reflections of sapphire to as low as 0.1% at 500 nm being deposited only on one side of the substrate. We also demonstrate that deposition of the second layer with higher porosity using block copolymers enables the design of graded-index double-layered coatings. AlO_x structures with just two layers and a total thickness of less than 200 nm are capable of reduction of Fresnel reflections under normal illumination to below 0.5% in a broad spectral range with 0.1% reflection at 700 nm. Additionally, and most importantly, we show that highly porous single-layer and graded-index double-layered ARCs are characterized by high hardness andmore » scratch resistivity. The hardness and the maximum reached load were 7.5 GPa and 13 mN with a scratch depth of about 130 nm, respectively, that is very promising for the structures consisting of two porous AlO_x layers with 50% and 85% porosities, correspondingly. Such mechanical properties of coatings can also allow their application as protective layers for other optical coatings.« less

Authors:

Ji, Cheng ^[1]; Zhang, Zhongbo  ^[1];

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• Search DOE PAGES for ORCID "0000-0001-5294-444X"

Omotosho, Khalil D. ^[2]; Berman, Diana  ^[2];

• Search DOE PAGES for author "Berman, Diana"
• Search DOE PAGES for ORCID "0000-0002-9320-9772"

Lee, Byeongdu  ^[3];

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• Search DOE PAGES for ORCID "0000-0003-2514-8805"

Divan, Ralu ^[4]; Guha, Supratik  ^[1];

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• Search DOE PAGES for ORCID "0000-0001-5071-8318"

Shevchenko, Elena V.  ^[5]

• Search DOE PAGES for author "Shevchenko, Elena V."
• Search DOE PAGES for ORCID "0000-0002-5565-2060"

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+ Show Author Affiliations

1. Argonne National Lab. (ANL), Argonne, IL (United States); Univ. of Chicago, IL (United States)
2. Univ. of North Texas, Denton, TX (United States). Advance Materials and Manufacturing Processes Institute (AMMPI)
3. Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
4. Argonne National Lab. (ANL), Argonne, IL (United States). Center for Nanoscale Materials
5. Argonne National Lab. (ANL), Argonne, IL (United States). Center for Nanoscale Materials; Univ. of Chicago, IL (United States). James Frank Institute

Publication Date:

Thu Sep 01 00:00:00 EDT 2022

Research Org.:

Argonne National Laboratory (ANL), Argonne, IL (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES); U.S. Department of Defense (DOD). Vannevar Bush Faculty Fellowship; US Department of the Navy, Office of Naval Research (ONR); National Science Foundation (NSF)

OSTI Identifier:

1969403

Grant/Contract Number:  

AC02-06CH11357

Resource Type:

Accepted Manuscript

Journal Name:

ACS Nano

Additional Journal Information:

Journal Volume: 16; Journal Issue: 9; Journal ID: ISSN 1936-0851

Publisher:

American Chemical Society (ACS)

Country of Publication:

United States

Language:

English

Subject:

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; anti-reflective coatings; optical coating; low refractive index; porous alumina; polymer of intrinsic microporosity; PIM-1; sequential infiltration synthesis; coating materials; deposition; layers; optical properties; porosity