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Preservation of the Morphology of a Self‐Encapsulated Thin Titania Film in a Functional Multilayer Stack: An X‐Ray Scattering Study
Author(s) -
Perlich Jan,
Memesa Mine,
Diethert Alexander,
Metwalli Ezzeldin,
Wang Weinan,
Roth Stephan V.,
Timmann Andreas,
Gutmann Jochen S.,
MüllerBuschbaum Peter
Publication year - 2009
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.200800800
Subject(s) - materials science , grazing incidence small angle scattering , thin film , nanostructure , nanotechnology , copolymer , scattering , chemical engineering , fabrication , calcination , etching (microfabrication) , spin coating , layer (electronics) , polymer , composite material , optics , small angle neutron scattering , organic chemistry , chemistry , medicine , catalysis , physics , neutron scattering , alternative medicine , engineering , pathology
Looks matter: Generally, the morphology of titania thin films is crucial for their performance, hence much effort is spent to tailor the desired morphology. X‐ray scattering enables the monitoring of the crystalline titania layer morphology during build‐up of the functional multilayer stack (see Figure). Herein evidence is provided that the morphology is preserved throughout the fabrication process.Tailoring of the titania morphology is achieved by the combination of a triblock copolymer, acting as structure‐directing agent, and a sol–gel chemistry enabling the incorporation of the provided inorganic material (titania) into the selected phase of the triblock copolymer. Spin‐coating of the solution on FTO‐coated glass, followed by plasma etching and calcination of the thin film results in the formation of self‐encapsulated crystalline titania nanostructures. The fabricated nanostructures are coated stepwise with dye, conductive polymers and gold forming a functional multilayer stack. An advanced small‐angle scattering technique probing the sample with X‐ray synchrotron radiation under grazing incidence (GISAXS) is employed for the characterization of the preparation route, as scattering allows accessing the structure inside the multilayers. The tailored titania morphology is preserved during the preparation route towards the functional multilayer stack of a photovoltaic demonstration cell. Two clearly distinguishable structures originate from the substrate and the titania templated by the triblock copolymer; hence the other layers induce no additional structures. Therefore, this investigation provides the evidence that the effort spent to tailor the morphology is justified by the preservation of the self‐encapsulated titania morphology that is created by the structure‐directing agent throughout the functional multilayer stack build‐up.