Title: Understanding Electron Transport in Disk-Shaped Triphenylene-Tris(naphthaleneimidazole)s through Structural Modification and Theoretical Investigation

Abstract

We report that disk-shaped molecules with large aromatic π-surfaces are a class of organic semiconductors in which the charge-carrier transport properties could be greatly facilitated by preferred intermolecular stacking of the π-surfaces. The optical and electronic properties are not only determined by the core aromatic structure of these disk-shaped molecules but are also strongly dependent on the side chains, which directly impact the molecular self-assembly behavior in condensed phases. Triphenylene-tris(naphthaleneimidazole) (TP-TNI) is a recently reported n-type semiconductor featuring a large π-core and branched side chains, with an electron-transporting mobility reaching 10^-4 cm² V^-1 s^-1. To further improve material performance, a detailed study is needed to understand the dependence of carrier transport properties on both the core electronic structure and side chain. Here, we present the detailed synthesis and characterization of a TP-TNI derivative bearing linear side chains, which has demonstrated a field-effect electron-transport mobility of up to 1.3 × 10^-3 cm² V^-1 s^-1. The more than 1 order improvement in electron-transport properties over the branched side chain homologue can be correlated to ordered twisted packing in the thin film, as revealed by in situ variable temperature grazing incidence wide-angle X-ray scattering studies. In conclusion, in-depth theoretical understanding of the frontiermore » orbitals, reorganization energies, and charge-transfer integrals of TP-TNI molecules has provided further insight into the relationship between the molecular stacking geometry and charge-transport properties.« less

Authors:

Zhang, Yue ^[1]; Hanifi, David A. ^[2]; Fernández-Liencres, M. Paz ^[3]; Klivansky, Liana M. ^[4]; Ma, Biwu  ^[5];

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• Search DOE PAGES for ORCID "0000-0003-1573-8019"

Navarro, Amparo ^[3]; Liu, Yi  ^[4]

• Search DOE PAGES for author "Liu, Yi"
• Search DOE PAGES for ORCID "0000-0002-3954-6102"

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+ Show Author Affiliations

1. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Nanjing Tech Univ. (China)
2. Stanford Univ., Palo Alto, CA (United States)
3. Universidad de Jaén, Campus Las Lagunillas (Spain)
4. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
5. Florida State Univ., Tallahassee, FL (United States)

Publication Date:

Fri Jun 02 00:00:00 EDT 2017

Research Org.:

Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1530289

Grant/Contract Number:  

AC02-05CH11231

Resource Type:

Accepted Manuscript

Journal Name:

ACS Applied Materials and Interfaces

Additional Journal Information:

Journal Volume: 9; Journal Issue: 23; Journal ID: ISSN 1944-8244

Publisher:

American Chemical Society (ACS)

Country of Publication:

United States

Language:

English

Subject:

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; 36 MATERIALS SCIENCE; charge transport; columnar stacking; disk-shaped molecules; n-type; organic semiconductor