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
Included in
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.