Uncovering the out-of-plane nanomorphology of organic photovoltaic bulk heterojunction by GTSAXS

AbstractThe bulk morphology of the active layer of organic solar cells (OSCs) is known to be crucial to the device performance. The thin film device structure breaks the symmetry into the in-plane direction and out-of-plane direction with respect to the substrate, leading to an intrinsic anisotropy in the bulk morphology. However, the characterization of out-of-plane nanomorphology within the active layer remains a grand challenge. Here, we utilized an X-ray scattering technique, Grazing-incident Transmission Small-angle X-ray Scattering (GTSAXS), to uncover this new morphology dimension. This technique was implemented on the model systems based on fullerene derivative (P3HT:PC71BM) and non-fullerene systems (PBDBT:ITIC, PM6:Y6), which demonstrated the successful extraction of the quantitative out-of-plane acceptor domain size of OSC systems. The detected in-plane and out-of-plane domain sizes show strong correlations with the device performance, particularly in terms of exciton dissociation and charge transfer. With the help of GTSAXS, one could obtain a more fundamental perception about the three-dimensional nanomorphology and new angles for morphology control strategies towards highly efficient photovoltaic devices.

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Synchrotron x-ray Scattering Study on Oxidation of AIN/Sapphire

MRS Proceedings ◽

10.1557/proc-590-195 ◽

1999 ◽

Vol 590 ◽

Cited By ~ 3

Author(s):

H. C. Kang ◽

S. H. Seo ◽

D. Y. Noh

Keyword(s):

Domain Size ◽

Film Plane ◽

Atomic Concentration ◽

X Ray ◽

X Ray Scattering ◽

Nano Crystalline ◽

Out Of Plane ◽

Plane Direction ◽

Scattering Study ◽

Ray Scattering

ABSTRACTWe present an x-ray scattering study of the oxidation of AIN/sapphire films into λ-A12O3 upon annealing. Epitaxial AIN/Sapphire(0001) transforms into nano-crystalline epitaxial λ-A12O3 during annealing at temperatures above 800°C in air. The crystalline orientational relation between the λ-Al2O3 and AIN are < 111 > // < 0001 > in the film normal direction, and < 110 > // < 1120 > in the film plane direction. The domain size of the spinel λ-A1203 crystalline is smaller than 50 Å in both out-of-plane and in-plane directions. The XPS depth profiles of the oxide film showed that the film is composed of aluminum and oxygen, and the atomic concentration ratio is about 2:3.

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Structural characterization of laser ablated epitaxial (Ba0.5Sr0.5)TiO3 thin films on MgO(001) by synchrotron x-ray scattering

Journal of Materials Research ◽

10.1557/jmr.1999.0388 ◽

1999 ◽

Vol 14 (7) ◽

pp. 2905-2911 ◽

Cited By ~ 11

Author(s):

Sangsub Kim ◽

Tae Soo Kang ◽

Jung Ho Je

Keyword(s):

Thin Films ◽

Early Stage ◽

Lattice Parameter ◽

Normal Direction ◽

X Ray ◽

X Ray Scattering ◽

Surface Normal ◽

Out Of Plane ◽

Axis Parallel ◽

Ray Scattering

Epitaxial (Ba0.5Sr0.5) TiO3 thin films of two different thickness (∼25 and ∼134 nm) on MgO(001) prepared by a pulsed laser deposition method were studied by synchrotron x-ray scattering measurements. The film grew initially with a cube-on-cube relationship, maintaining it during further growth. As the film grew, the surface of the film became significantly rougher, but the interface between the film and the substrate did not. In the early stage of growth, the film was highly strained in a tetragonal structure (c/a = 1.04) with the longer axis parallel to the surface normal direction. As the growth proceeded further, it relaxed to a cubic structure with the lattice parameter near the bulk value, and the mosaic distribution improved significantly in both in- and out-of-plane directions. The thinner film (∼25 nm) showed only one domain limited mainly by the film thickness, but the thicker film (∼134 nm) exhibited three domains along the surface normal direction.

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Markedly different molecular formation in DPP-based small-molecule solar cells probed by grazing-incidence wide-angle X-ray scattering

Acta Crystallographica Section B Structural Science Crystal Engineering and Materials ◽

10.1107/s2052520617009933 ◽

2017 ◽

Vol 73 (5) ◽

pp. 916-922

Author(s):

Yu Jin Kim ◽

Chang Eun Song ◽

Sanjaykumar R. Suranagi ◽

Jong-Cheol Lee ◽

Chan Eon Park

Keyword(s):

Solar Cells ◽

Small Molecule ◽

Molecular Design ◽

Grazing Incidence ◽

Fullerene Derivative ◽

Wide Angle ◽

Performance Property ◽

X Ray ◽

X Ray Scattering ◽

Ray Scattering

This study comprehensively explores the nanostructural properties of two diketopyrrolo[3,4-c]pyrrole-1,4-dione (DPP)-based small molecules with different alkyl side groups and their blends with the fullerene derivative PC71BM, using grazing-incidence wide-angle X-ray scattering synchrotron techniques. Preferentially relative face-on orientation within the larger and more ordered stacking phase of SM1 with its shorter side group (ethylhexyl) was observed in the majority of both pristine and blend thin films, whereas SM2 crystals showed strictly perpendicular orientation. These contrasting crystalline characteristics led to significant differences in the results, from which crystalline structure–performance property correlations are proposed. Thus, the results not only demonstrate important scientific insights into the relationship between molecular structure and crystalline formation but also provide molecular design directions that will facilitate further improvement to the morphology and performance of DPP-based small-molecule solar cells.

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Microscopic Structure Analysis in Disordered Materials using Anomalous X-ray Scattering

Zeitschrift für Physikalische Chemie ◽

10.1515/zpch-2014-0555 ◽

2014 ◽

Vol 228 (10-12) ◽

Cited By ~ 5

Author(s):

Jens Rüdiger Stellhorn ◽

Shinya Hosokawa ◽

Wolf-Christian Pilgrim

Keyword(s):

Materials Science ◽

High Reliability ◽

Structural Characteristics ◽

Chemical Species ◽

Model Systems ◽

X Ray Diffraction ◽

Basic Principles ◽

X Ray ◽

X Ray Scattering ◽

Ray Scattering

AbstractAlthough X-ray diffraction is still mainly used to determine crystal structures, the demand for an understanding of the atomic arrangement in disordered matter has progressively become more important over the past decades. However, apart from simple model systems, it is still a challenging task to unravel the microscopic ordering of the atoms in amorphous multi-component materials, although this knowledge becomes increasingly important in modern materials science, in which the physical properties are often related to the microscopic ordering of the different chemical species of the substance. This article reports about the combination of Anomalous X-ray Scattering (AXS) with Reverse Monte Carlo Computer simulation (RMC) as a proper tool to precisely determine the microscopic structural characteristics in such systems with high reliability. The basic principles of the method will be illustrated and some examples of modern materials will be given to proof the applicability and the capability of this method.

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Lattice Relaxation of Eras/Gaas: An X-Ray Scattering Study

MRS Proceedings ◽

10.1557/proc-202-579 ◽

1990 ◽

Vol 202 ◽

Cited By ~ 1

Author(s):

P. F. Miceli ◽

K. W. Moyers ◽

C. J. Palmstrøm

Keyword(s):

Lattice Relaxation ◽

Epitaxial Layers ◽

Misfit Dislocations ◽

X Ray ◽

X Ray Scattering ◽

Ideal System ◽

Out Of Plane ◽

Scattering Study ◽

Interference Oscillations ◽

Ray Scattering

ABSTRACTThe results of a high resolution x-ray scattering study of [001]ErAs epitaxial layers grown on [001]GaAs is presented. ErAs is pseudomorphic on GaAs for thicknesses below 70Å and, for thicker films, lattice relaxation is oberved concomitant with an Increase of the In-plane mosaic due to the formation of misfit dislocations. Above 300Å, the out-of-plane transverse scattering from the ErAs lattice planes Is no longer specular and further relaxation Is related to the out-of-plane mosaic. The ratio of elastic constants, C12/C11, Is determined to be 0.126 and the thermal expansion was measured. Thin film Interference oscillations are observed and modeled. ErAs/GaAs Is an Ideal system for x-ray scattering studies of lattice relaxation and structure in epitaxial layers. Films as thin as 20Å have been studied.

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Synchrotron X-Ray Scattering of (Ba0.5Sr0.5)TiO3 Thin Films Epitaxially Grown on MgO(100)

MRS Proceedings ◽

10.1557/proc-541-53 ◽

1998 ◽

Vol 541 ◽

Author(s):

Sang S. Kim ◽

Jung H. Je

Keyword(s):

Thin Films ◽

Early Stage ◽

Lattice Parameter ◽

Normal Direction ◽

X Ray ◽

X Ray Scattering ◽

Surface Normal ◽

Out Of Plane ◽

Axis Parallel ◽

Ray Scattering

Abstract((Ba0.5Sr 0.5)TiO3 thin films of two different thicknesses (∼ 250 Å and ∼ 1330 Å) epitaxially prepared on MgO(100) using pulsed laser deposition were studied by synchrotron x-ray scattering measurements. The film initially grew on MgO(100) with a cube-on-cube relationship, maintaining it during further growth. As the film grew, the surface of the film became rougher significantly, but the interface between the film and the substrate did not change so much. In the early stage, the film was highly strained in a tetragonal structure with the longer axis parallel to the surface normal direction. As the growth proceeded further, it was mostly relaxed to a cubic structure with the lattice parameter of the bulk value and the mosaic distribution improved significantly in both the in-plane and the out-of-plane directions. The thinner film showed only one domain limited mainly by the film thickness, but the thicker film exhibited three domains along the surface normal direction.

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Real-time synchrotron x-ray scattering study of an epitaxial BaTiO3 thin film during heating

Journal of Materials Research ◽

10.1557/jmr.1999.0504 ◽

1999 ◽

Vol 14 (9) ◽

pp. 3734-3738 ◽

Cited By ~ 10

Author(s):

Sang Sub Kim ◽

Jung Ho Je

Keyword(s):

Real Time ◽

Structural Characteristics ◽

Film Surface ◽

Single Crystal Substrate ◽

X Ray ◽

X Ray Scattering ◽

Out Of Plane ◽

Crystal Substrate ◽

Magnetron Sputter Deposition ◽

Ray Scattering

An epitaxial BaTiO3 film with 290-nm thickness was prepared on a MgO(001) single-crystal substrate by radio-frequency magnetron sputter deposition. The structural characteristics of the film were studied as a function of temperature in in situ, real-time synchroton x-ray scattering experiments. We found that the as-grown film was strained at room temperature and tetragonally distorted with the c axis normal to the film surface. Interestingly, its lattice parameters were found to be expanded 1.28% and 0.64% in both the in-plane and the out-of-plane directions, respectively (i.e., biaxially), comparing to those of a bulk BaTiO3. More importantly, as it was heated to 600 °C, the tetragonal structure was kept up without the phase transition, which is usually observed in other epitaxial ferroelectric thin films.

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High Resolution X-Ray Scattering Studies of Strain in Epitaxial Thin Films of Yttrium Silicide Grown on Silicon(111)

MRS Proceedings ◽

10.1557/proc-160-287 ◽

1989 ◽

Vol 160 ◽

Cited By ~ 2

Author(s):

L. J. Martinez-Miranda ◽

M. P. Siegal ◽

P. A. Heiney ◽

J. J. Santiago-Aviles ◽

W. R. Graham

Keyword(s):

Thin Films ◽

High Resolution ◽

Grazing Incidence ◽

Lattice Parameters ◽

Epitaxial Thin Films ◽

X Ray ◽

X Ray Scattering ◽

Areal Coverage ◽

Out Of Plane ◽

Ray Scattering

AbstractWe have used high resolution grazing incidence x-ray scattering (GIXS) to study the in-plane and out-of-plane structure of epitaxial YSi2-x films grown on Si (111), with thicknesses ranging from 85Å to 510Å. Our results indicate that the films are strained, and that film strain increases as a function of thickness, with lattice parameters varying from a = 3.846Å/c = 4.142Å for the 85Å film to a = 3.877Å/c = 4.121Å for the 510Å film. We correlate these results with an increase in pinhole areal coverage as a function of thickness. In addition, our measurements show no evidence for the existence of ordered silicon vacancies in the films.

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Experimentally consistent atomistic modeling of bulk and local structure in liquids and disordered materials by empirical potential structure refinement

Pure and Applied Chemistry ◽

10.1351/pac200880061211 ◽

2008 ◽

Vol 80 (6) ◽

pp. 1211-1227 ◽

Cited By ~ 6

Author(s):

Daniel T. Bowron

Keyword(s):

Structure Refinement ◽

Solution Chemistry ◽

Model Systems ◽

Scattering Data ◽

Liquid Gallium ◽

X Ray ◽

Empirical Potential ◽

X Ray Scattering ◽

Potential Structure ◽

Ray Scattering

This article presents an overview of the use of the empirical potential structure refinement (EPSR) technique for generating three-dimensional atomistic models of liquids and structurally disordered solids that are consistent with experimental neutron and X-ray scattering data. The extension of this technique through the calculation of extended X-ray absorption fine structure (EXAFS) spectra is outlined, and the benefits of this are demonstrated for a range of systems and in particular for our ability to address structural questions of importance in solution chemistry. The model systems chosen as examples for structural analysis are (i) liquid gallium, (ii) silica glass, and (iii) a 1 m aqueous solution of YCl3. The advantages of this analytical approach for addressing chemically specific structural questions in disordered systems are discussed within the context of the experimental alternatives based on the techniques of neutron scattering with isotopic substitution and anomalous X-ray scattering.

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