Strain-Work Function Relationship in Single-Crystal Tetracene

TY - JOUR

T1 - Strain-Work Function Relationship in Single-Crystal Tetracene

AU - Zhang, Zhuoran

AU - Yu, Guichuan

AU - Garcia-Barriocanal, Javier

AU - Xie, Zuoti

AU - Frisbie, C. Daniel

N1 - Publisher Copyright: © 2020 American Chemical Society.

PY - 2020/9/9

Y1 - 2020/9/9

N2 - Understanding the impact of strain on organic semiconductors is important for the development of electronic devices and sensors that are subject to environmental changes and mechanical stimuli; it is also important for understanding the fundamental mechanisms of charge trapping. Following our previous study on the strain effects in rubrene, we present here only the second example of the strain-work function relationship in an organic semiconductor; in this case, the benchmark material tetracene. Thin, platelike single crystals of tetracene with large (001) facets were laminated onto silicon and rubber substrates having significantly different coefficients of thermal expansion; mechanical strain in tetracene was subsequently induced by varying the temperature of the assembly. Tensile and compressive strains parallel to the (001) major facet were measured by grazing incidence X-ray diffraction, and the corresponding shifts in the electronic work functions were recorded via scanning Kelvin probe microscopy (SKPM). The work function of the tetracene (001) crystal surface directly correlated with the net mechanical strain and increased by ∼100 meV for in-plane tensile strains of 0.1% and decreased by approximately the same amount for in-plane compressive strains of -0.1%. This work provides evidence of the general and important impact of strain on the electrical properties of van der Waals bonded crystalline organic semiconductors and thereby supports the hypothesis that heterogeneous strains, for example in thin films, can be a major source of static electronic disorder.

AB - Understanding the impact of strain on organic semiconductors is important for the development of electronic devices and sensors that are subject to environmental changes and mechanical stimuli; it is also important for understanding the fundamental mechanisms of charge trapping. Following our previous study on the strain effects in rubrene, we present here only the second example of the strain-work function relationship in an organic semiconductor; in this case, the benchmark material tetracene. Thin, platelike single crystals of tetracene with large (001) facets were laminated onto silicon and rubber substrates having significantly different coefficients of thermal expansion; mechanical strain in tetracene was subsequently induced by varying the temperature of the assembly. Tensile and compressive strains parallel to the (001) major facet were measured by grazing incidence X-ray diffraction, and the corresponding shifts in the electronic work functions were recorded via scanning Kelvin probe microscopy (SKPM). The work function of the tetracene (001) crystal surface directly correlated with the net mechanical strain and increased by ∼100 meV for in-plane tensile strains of 0.1% and decreased by approximately the same amount for in-plane compressive strains of -0.1%. This work provides evidence of the general and important impact of strain on the electrical properties of van der Waals bonded crystalline organic semiconductors and thereby supports the hypothesis that heterogeneous strains, for example in thin films, can be a major source of static electronic disorder.

KW - X-ray diffraction

KW - organic semiconductors

KW - scanning Kelvin probe microscopy

KW - single crystal

KW - strain

KW - work function

UR - http://www.scopus.com/inward/record.url?scp=85090869515&partnerID=8YFLogxK

U2 - 10.1021/acsami.0c11566

DO - 10.1021/acsami.0c11566

M3 - 文章

C2 - 32805858

AN - SCOPUS:85090869515

SN - 1944-8244

VL - 12

SP - 40607

EP - 40612

JO - ACS applied materials & interfaces

JF - ACS applied materials & interfaces

IS - 36

ER -