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This content will become publicly available on December 11, 2018

Title: On the Effect of Confinement on the Structure and Properties of Small-Molecular Organic Semiconductors

Many typical organic optoelectronic devices, such as light-emitting diodes, field-effect transistors, and photovoltaic cells, use an ultrathin active layer where the organic semiconductor is confined within nanoscale dimensions. However, the question of how this spatial constraint impacts the active material is rarely addressed, although it may have a drastic influence on the phase behavior and microstructure of the active layer and hence the final performance. Here, the small-molecule semiconductor p-DTS(FBTTh 2) 2 is used as a model system to illustrate how sensitive this class of material can be to spatial confinement on device-relevant length scales. It is also shown that this effect can be exploited; it is demonstrated, for instance, that spatial confinement is an efficient tool to direct the crystal orientation and overall texture of p-DTS(FBTTh 2) 2 structures in a controlled manner, allowing for the manipulation of properties including photoluminescence and charge transport characteristics. This insight should be widely applicable as the temperature/confinement phase diagrams established via differential scanning calorimetry and grazing-incidence X-ray diffraction are used to identify specific processing routes that can be directly extrapolated to other functional organic materials, such as polymeric semiconductors, ferroelectrics or high-refractive-index polymers, to induce desired crystal textures or specific (potentially new)more » polymorphs.« less
ORCiD logo [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [4] ; ORCiD logo [6] ;  [3] ;  [7] ;  [8]
  1. Imperial College, London (United Kingdom); Univ. of Basque Country, Donostia-San Sebastian (Spain)
  2. Imperial College, London (United Kingdom)
  3. National Renewable Energy Lab. (NREL), Golden, CO (United States); Univ. of Colorado, Boulder, CO (United States)
  4. Cornell Univ., Ithaca, NY (United States)
  5. Inst. de Estructura de la Materia IEM-CSIC, Madrid (Spain)
  6. Georgia Inst. of Technology, Atlanta, GA (United States)
  7. King Abdullah Univ. of Science and Technology (KAUST), Thuwal (Saudi Arabia). KAUST Solar Center (KSC)
  8. Imperial College, London (United Kingdom); Georgia Inst. of Technology, Atlanta, GA (United States)
Publication Date:
Report Number(s):
Journal ID: ISSN 2199-160X
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Advanced Electronic Materials
Additional Journal Information:
Journal Volume: 4; Journal Issue: 1; Journal ID: ISSN 2199-160X
Research Org:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
14 SOLAR ENERGY; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; AAO; confinement; crystallization; organic semiconductors; phase diagrams
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1412595