Title: Inducing Molecular Aggregation of Polymer Semiconductors in a Secondary Insulating Polymer Matrix to Enhance Charge Transport

Abstract

Polymer semiconductors (PSCs) are a desirable class of materials for next-generation electronics. However, the conformational complexity associated with macromolecules, as well as the presence of unique inter- and intrachain interactions, make it challenging to control the morphology of PSCs. Previously, it has been reported that beyond a certain molecular weight, thin-film charge carrier mobility typically drops due to reduced crystallinity and increased entanglement. In this work, the use of an insulating secondary matrix polymer, polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene (SEBS), is shown to induce molecular ordering of PSCs across multiple length scales. Aggregation-induced molecular ordering in SEBS/PSC hybrid films is strongly correlated to the molecular weight of the semiconducting component. The higher the molecular weight of PSC used to blend with SEBS, the greater the observed improvement in polymer aggregation and orientation. This leads to a 5-fold increase of charge carrier mobility, from 0.3 to 1.5 cm2 V^–1 s^–1 (P-97k), in field-effect transistors (FETs) with only 30 wt % of the semiconducting polymer in SEBS. Moreover, mobility can be further elevated to 2 cm2 V^–1 s^–1 using an extensional flow-driven solution shearing deposition method. The findings here on using a secondary polymer matrix to dramatically improve the molecular organization and charge transport of a high-molecular-weight PSC are a useful morphological control strategy. It can also be carried out using nonhalogenated solvents, such as $$p$$-xylene, which are more environmentally benign and industrially relevant than commonly used chlorinated solvents.

Authors:

Nikzad, Shayla  ^[1];

• Search DOE PAGES for author "Nikzad, Shayla"
• Search DOE PAGES for ORCID "0000-0001-9416-4601"

Wu, Hung-Chin  ^[1];

• Search DOE PAGES for author "Wu, Hung-Chin"
• Search DOE PAGES for ORCID "0000-0001-6492-0525"

Kim, Jenny ^[2]; Mahoney, Christine M. ^[2]; Matthews, James R. ^[2]; Niu, Weijun ^[2]; Li, Yang ^[2]; Wang, Hongxiang ^[2]; Chen, Wen-Chang  ^[3];

• Search DOE PAGES for author "Chen, Wen-Chang"
• Search DOE PAGES for ORCID "0000-0003-3170-7220"

Toney, Michael F.  ^[4];

• Search DOE PAGES for author "Toney, Michael F."
• Search DOE PAGES for ORCID "0000-0002-7513-1166"

He, Mingqian  ^[2];

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• Search DOE PAGES for ORCID "0000-0002-9387-9928"

Bao, Zhenan  ^[1]

• Search DOE PAGES for author "Bao, Zhenan"
• Search DOE PAGES for ORCID "0000-0002-0972-1715"

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+ Show Author Affiliations

1. Stanford Univ., CA (United States)
2. Corning Incorporated, Corning, NY (United States)
3. National Taiwan Univ., Taipei (Taiwan)
4. SLAC National Accelerator Lab., Menlo Park, CA (United States). Stanford Synchrotron Radiation Lightsource (SSRL)

Publication Date:

Fri Jan 03 00:00:00 EST 2020

Research Org.:

SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States). Stanford Synchrotron Radiation Lightsource (SSRL); Stanford Univ., CA (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES); Ministry of Science and Technology of Taiwan; National Science Foundation (NSF)

OSTI Identifier:

1605283

Alternate Identifier(s):

OSTI ID: 1782829; OSTI ID: 1985486

Grant/Contract Number:  

AC02-76SF00515; SC0016523; MOST 106-2917-I-564-023; ECCS-1542152

Resource Type:

Accepted Manuscript

Journal Name:

Chemistry of Materials

Additional Journal Information:

Journal Volume: 32; Journal Issue: 2; Journal ID: ISSN 0897-4756

Publisher:

American Chemical Society (ACS)

Country of Publication:

United States

Language:

English

Subject:

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Polymer solutions; Polymer morphology; Thin films; Carrier dynamics; Polymers