title: Intermolecular Ordering in Organic Semiconductor Layers and its Correlation to Electronic Properties
creator: Nanova, Diana
subject: ddc-500
subject: 500 Natural sciences and mathematics
subject: ddc-530
subject: 530 Physics
description: This thesis examines the influence of the morphology of organic semiconductors on their electronic properties using  analytical transmission electron microscopy (TEM). For the first time, the dielectric properties of organic materials are derived from electron energy loss spectroscopy. A correlation between electron diffraction and current transient measurements of the solution processed polymer poly(3-hexylthiophene) indicates that the semicrystalline  structure of the polymer leads to anisotropic charge transport. The study further investigates the structural properties of co-evaporated small molecule blends of  fluorinated zincphtalocyanine (F4ZnPc) and fullerene (C60) on different substrates. Energy filtered TEM reveales strong fullerene agglomeration for all substrates  considered here, which is shown to be facilitated by an elevated substrate temperature (100°C). These agglomerates are still largely amorphous if the blend is grown on  a pristine F4ZnPc layer as required for non-inverted solar cells. However, on an underlying C60-layer, as is typically used for inverted devices, a pronounced order  of the fullerene is observed. Device characterization indicates that the highly pure and crystalline C60 domains improve free charge carrier generation and solar cell  efficiency. This thesis therefore provides a novel explanation why record efficiencies in small molecule solar cells are only achieved in inverted devices.
date: 2015
type: Dissertation
type: info:eu-repo/semantics/doctoralThesis
type: NonPeerReviewed
format: application/pdf
identifier: https://archiv.ub.uni-heidelberg.de/volltextserverhttps://archiv.ub.uni-heidelberg.de/volltextserver/18727/1/Dissertation_Diana_Nanova.pdf
identifier: DOI:10.11588/heidok.00018727
identifier: urn:nbn:de:bsz:16-heidok-187274
identifier:   Nanova, Diana  (2015) Intermolecular Ordering in Organic Semiconductor Layers and its Correlation to Electronic Properties.  [Dissertation]     
relation: https://archiv.ub.uni-heidelberg.de/volltextserver/18727/
rights: info:eu-repo/semantics/openAccess
rights: http://archiv.ub.uni-heidelberg.de/volltextserver/help/license_urhg.html
language: eng