Title: Significant charge transport effects due to subtle molecular changes in nitroxide radical single crystals

Journal Article · · Cell Reports Physical Science

Radical-containing materials have received renewed interest due to their charge-conducting properties. However, most work focuses on macromolecules, while less attention has been paid to radical-containing small molecules. Here, we quantify the electrical conductivity in two organic radical single crystals and demonstrate that a subtle change in atomic connectivity drastically alters the macroscopic electronic properties of the materials. One radical crystal has an electrical conductivity of 3S m–1, which is the among the highest values for nonconjugated radical conductors over a 1 μm scale. However, the other radical crystal has a 1,000-fold lower conductivity, despite their extremely similar molecular structures. The temperature-dependent conductivity follows the variable range hopping mechanism for both radical crystals, and the difference in effective charge mobility is the reason for the conductivity difference. These results present a clear picture of the design rules and charge transport mechanism for radical-based small-molecule materials.

Research Organization:
Purdue University, West Lafayette, IN (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
Grant/Contract Number:
SC0021967
OSTI ID:
1991494
Journal Information:
Cell Reports Physical Science, Journal Name: Cell Reports Physical Science Journal Issue: 5 Vol. 4; ISSN 2666-3864
Publisher:
ElsevierCopyright Statement
Country of Publication:
United States
Language:
English

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