Crossed 2D versus Slipped 1D π-Stacking in Polymorphs of Crystalline Organic Thin Films: Impact on the Electronic and Optical Response

María José Aliaga-Gosalvez, Nicola Demitri, Michael Dohr, Juan Carlos Roldao, Sang Kyu Park, Sangyoon Oh, Shinto Varghese, Soo Young Park, Yoann Olivier, Begoña Milián-Medina, Roland Resel, Johannes Gierschner

Research output: Contribution to journalArticle

Abstract

Polymorphs of organic semiconductors are of great interest as they shed light to structure-property relationships. The full X-ray thin film structure analysis of two polymorphs (B, G) of an important n-type semiconducting dicyano-distyrylbenzene based small molecule (CN-TFPA) is reported. Drastically different structures of the monotropic phases are revealed, that is an uncommon 2D crossed π-stacked arrangement for the B-phase versus a 1D slipped π-stack for G. Both phases exhibit a layered structure in the (100) plane with high structural integrity, driven by the hydrophobic contacts of the terminal CF3 groups; as (100) coincides with the film surface, this allows for exfoliation by scotch tape. An in-depth time-dependent density functional theory (TD-DFT) based quantum mechanics/molecular mechanics (QM/MM) study reveals all subsequent significantly differing optical and electronic responses which result from the different arrangements: the B film shows little excitonic interaction with strong blue fluorescence, amplified spontaneous emission (ASE), and good 2D n-type transport. The G film forms H-aggregates with strong green fluorescence, no ASE, and 1D n-type charge transport. The established structure-property relationships are seen as a crucial step for computer-aided device analysis.

Original languageEnglish
Article number1900749
JournalAdvanced Optical Materials
Volume7
Issue number21
DOIs
Publication statusPublished - 1 Nov 2019

Fingerprint

Crystallization
Polymorphism
Spontaneous emission
Crystalline materials
Thin films
spontaneous emission
thin films
Fluorescence
electronics
X ray films
fluorescence
Molecular mechanics
Semiconducting organic compounds
Quantum theory
organic semiconductors
Structural integrity
integrity
Tapes
tapes
Density functional theory

Keywords

  • fluorescent materials
  • organic optoelectronics
  • organic semiconductor
  • photophysics
  • thin film polymorphism
  • two-dimensional (2D) charge transport

Cite this

Aliaga-Gosalvez, María José ; Demitri, Nicola ; Dohr, Michael ; Roldao, Juan Carlos ; Park, Sang Kyu ; Oh, Sangyoon ; Varghese, Shinto ; Park, Soo Young ; Olivier, Yoann ; Milián-Medina, Begoña ; Resel, Roland ; Gierschner, Johannes. / Crossed 2D versus Slipped 1D π-Stacking in Polymorphs of Crystalline Organic Thin Films : Impact on the Electronic and Optical Response. In: Advanced Optical Materials. 2019 ; Vol. 7, No. 21.
@article{890e5c15158e401b8fadd7a2f3e58337,
title = "Crossed 2D versus Slipped 1D π-Stacking in Polymorphs of Crystalline Organic Thin Films: Impact on the Electronic and Optical Response",
abstract = "Polymorphs of organic semiconductors are of great interest as they shed light to structure-property relationships. The full X-ray thin film structure analysis of two polymorphs (B, G) of an important n-type semiconducting dicyano-distyrylbenzene based small molecule (CN-TFPA) is reported. Drastically different structures of the monotropic phases are revealed, that is an uncommon 2D crossed π-stacked arrangement for the B-phase versus a 1D slipped π-stack for G. Both phases exhibit a layered structure in the (100) plane with high structural integrity, driven by the hydrophobic contacts of the terminal CF3 groups; as (100) coincides with the film surface, this allows for exfoliation by scotch tape. An in-depth time-dependent density functional theory (TD-DFT) based quantum mechanics/molecular mechanics (QM/MM) study reveals all subsequent significantly differing optical and electronic responses which result from the different arrangements: the B film shows little excitonic interaction with strong blue fluorescence, amplified spontaneous emission (ASE), and good 2D n-type transport. The G film forms H-aggregates with strong green fluorescence, no ASE, and 1D n-type charge transport. The established structure-property relationships are seen as a crucial step for computer-aided device analysis.",
keywords = "fluorescent materials, organic optoelectronics, organic semiconductor, photophysics, thin film polymorphism, two-dimensional (2D) charge transport",
author = "Aliaga-Gosalvez, {Mar{\'i}a Jos{\'e}} and Nicola Demitri and Michael Dohr and Roldao, {Juan Carlos} and Park, {Sang Kyu} and Sangyoon Oh and Shinto Varghese and Park, {Soo Young} and Yoann Olivier and Bego{\~n}a Mili{\'a}n-Medina and Roland Resel and Johannes Gierschner",
year = "2019",
month = "11",
day = "1",
doi = "10.1002/adom.201900749",
language = "English",
volume = "7",
journal = "Advanced Optical Materials",
issn = "2195-1071",
publisher = "John Wiley and Sons Inc.",
number = "21",

}

Aliaga-Gosalvez, MJ, Demitri, N, Dohr, M, Roldao, JC, Park, SK, Oh, S, Varghese, S, Park, SY, Olivier, Y, Milián-Medina, B, Resel, R & Gierschner, J 2019, 'Crossed 2D versus Slipped 1D π-Stacking in Polymorphs of Crystalline Organic Thin Films: Impact on the Electronic and Optical Response', Advanced Optical Materials, vol. 7, no. 21, 1900749. https://doi.org/10.1002/adom.201900749

Crossed 2D versus Slipped 1D π-Stacking in Polymorphs of Crystalline Organic Thin Films : Impact on the Electronic and Optical Response. / Aliaga-Gosalvez, María José; Demitri, Nicola; Dohr, Michael; Roldao, Juan Carlos; Park, Sang Kyu; Oh, Sangyoon; Varghese, Shinto; Park, Soo Young; Olivier, Yoann; Milián-Medina, Begoña; Resel, Roland; Gierschner, Johannes.

In: Advanced Optical Materials, Vol. 7, No. 21, 1900749, 01.11.2019.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Crossed 2D versus Slipped 1D π-Stacking in Polymorphs of Crystalline Organic Thin Films

T2 - Impact on the Electronic and Optical Response

AU - Aliaga-Gosalvez, María José

AU - Demitri, Nicola

AU - Dohr, Michael

AU - Roldao, Juan Carlos

AU - Park, Sang Kyu

AU - Oh, Sangyoon

AU - Varghese, Shinto

AU - Park, Soo Young

AU - Olivier, Yoann

AU - Milián-Medina, Begoña

AU - Resel, Roland

AU - Gierschner, Johannes

PY - 2019/11/1

Y1 - 2019/11/1

N2 - Polymorphs of organic semiconductors are of great interest as they shed light to structure-property relationships. The full X-ray thin film structure analysis of two polymorphs (B, G) of an important n-type semiconducting dicyano-distyrylbenzene based small molecule (CN-TFPA) is reported. Drastically different structures of the monotropic phases are revealed, that is an uncommon 2D crossed π-stacked arrangement for the B-phase versus a 1D slipped π-stack for G. Both phases exhibit a layered structure in the (100) plane with high structural integrity, driven by the hydrophobic contacts of the terminal CF3 groups; as (100) coincides with the film surface, this allows for exfoliation by scotch tape. An in-depth time-dependent density functional theory (TD-DFT) based quantum mechanics/molecular mechanics (QM/MM) study reveals all subsequent significantly differing optical and electronic responses which result from the different arrangements: the B film shows little excitonic interaction with strong blue fluorescence, amplified spontaneous emission (ASE), and good 2D n-type transport. The G film forms H-aggregates with strong green fluorescence, no ASE, and 1D n-type charge transport. The established structure-property relationships are seen as a crucial step for computer-aided device analysis.

AB - Polymorphs of organic semiconductors are of great interest as they shed light to structure-property relationships. The full X-ray thin film structure analysis of two polymorphs (B, G) of an important n-type semiconducting dicyano-distyrylbenzene based small molecule (CN-TFPA) is reported. Drastically different structures of the monotropic phases are revealed, that is an uncommon 2D crossed π-stacked arrangement for the B-phase versus a 1D slipped π-stack for G. Both phases exhibit a layered structure in the (100) plane with high structural integrity, driven by the hydrophobic contacts of the terminal CF3 groups; as (100) coincides with the film surface, this allows for exfoliation by scotch tape. An in-depth time-dependent density functional theory (TD-DFT) based quantum mechanics/molecular mechanics (QM/MM) study reveals all subsequent significantly differing optical and electronic responses which result from the different arrangements: the B film shows little excitonic interaction with strong blue fluorescence, amplified spontaneous emission (ASE), and good 2D n-type transport. The G film forms H-aggregates with strong green fluorescence, no ASE, and 1D n-type charge transport. The established structure-property relationships are seen as a crucial step for computer-aided device analysis.

KW - fluorescent materials

KW - organic optoelectronics

KW - organic semiconductor

KW - photophysics

KW - thin film polymorphism

KW - two-dimensional (2D) charge transport

UR - http://www.scopus.com/inward/record.url?scp=85070722942&partnerID=8YFLogxK

U2 - 10.1002/adom.201900749

DO - 10.1002/adom.201900749

M3 - Article

AN - SCOPUS:85070722942

VL - 7

JO - Advanced Optical Materials

JF - Advanced Optical Materials

SN - 2195-1071

IS - 21

M1 - 1900749

ER -