Co-Author(s)

Doran, Haley; Littleton, Matthew; Patrick, David L.

Research Mentor(s)

Patrick, David L.

Description

The ability to fabricate complex submicron-scale components from inorganic crystalline semiconductor materials such as c-Si enables countless modern technologies, from microelectromechanical systems to integrated circuits. For single-crystal molecular materials on the other hand, comparable approaches to defining micron- and submicron-scale structure are much less well developed, in part because weak intermolecular binding forces make molecular crystals vulnerable to damage by conventional techniques such as reactive ion etching, wet etching, and energetic beam milling. Here we show how the same weak forces that are problematic for top-down patterning of molecular crystals can be exploited to enable controlled bottom-up growth, by leveraging shape plasticity. We describe a new approach to molecular single-crystal engineering based on bottom-up growth of single-crystals on sacrificial templates by vapor-liquid-solid (VLS) deposition. We demonstrate that, under the right conditions, these templates can essentially serve as a mold for crystal formation, enabling growth of molecular single-crystals with complex, even extraordinary shapes. The resulting new class of materials may help unlock functional features for molecular single-crystals previously reserved for inorganic solids, via microstructural control over their photonic, thermal, charge transport, mechanical, and other fundamentally interesting and technologically valuable properties. Results are presented demonstrating a wide range of shape- and size-control modalities, including crystal topology, bounding perimeter shape, and nucleation position, for several families of small-molecule organic semiconductor and pharmaceutical compounds.

Document Type

Event

Start Date

15-5-2019 9:00 AM

End Date

15-5-2019 5:00 PM

Location

Carver Gym (Bellingham, Wash.)

Department

Chemistry

Genre/Form

student projects, posters

Subjects – Topical (LCSH)

Organic semiconductors; Photonics; Crystals--Plastic properties

Type

Image

Keywords

Organic molecular crystals, micropatterning, phononics, plasmonics, organic field-effect transistors, organic light emitting diodes

Rights

Copying of this document in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this document for commercial purposes, or for financial gain, shall not be allowed without the author’s written permission.

Language

English

Format

application/pdf

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May 15th, 9:00 AM May 15th, 5:00 PM

Bottom-Up Shape Engineering of Organic Molecular Single-Crystals

Carver Gym (Bellingham, Wash.)

The ability to fabricate complex submicron-scale components from inorganic crystalline semiconductor materials such as c-Si enables countless modern technologies, from microelectromechanical systems to integrated circuits. For single-crystal molecular materials on the other hand, comparable approaches to defining micron- and submicron-scale structure are much less well developed, in part because weak intermolecular binding forces make molecular crystals vulnerable to damage by conventional techniques such as reactive ion etching, wet etching, and energetic beam milling. Here we show how the same weak forces that are problematic for top-down patterning of molecular crystals can be exploited to enable controlled bottom-up growth, by leveraging shape plasticity. We describe a new approach to molecular single-crystal engineering based on bottom-up growth of single-crystals on sacrificial templates by vapor-liquid-solid (VLS) deposition. We demonstrate that, under the right conditions, these templates can essentially serve as a mold for crystal formation, enabling growth of molecular single-crystals with complex, even extraordinary shapes. The resulting new class of materials may help unlock functional features for molecular single-crystals previously reserved for inorganic solids, via microstructural control over their photonic, thermal, charge transport, mechanical, and other fundamentally interesting and technologically valuable properties. Results are presented demonstrating a wide range of shape- and size-control modalities, including crystal topology, bounding perimeter shape, and nucleation position, for several families of small-molecule organic semiconductor and pharmaceutical compounds.

 

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