Dataset Information

Directed Self-Assembly on Photo-Crosslinked Polystyrene Sub-Layers: Nanopattern Uniformity and Orientation.

ABSTRACT: A photo-crosslinked polystyrene (PS) thin film is investigated as a potential guiding sub-layer for polystyrene-block-poly (methyl methacrylate) block copolymer (BCP) cylindrical nanopattern formation via topographic directed self-assembly (DSA). When compared to a non-crosslinked PS brush sub-layer, the photo-crosslinked PS sub-layer provided longer correlation lengths of the BCP nanostructure, resulting in a highly uniform DSA nanopattern with a low number of BCP dislocation defects. Depending on the thickness of the sub-layer used, parallel or orthogonal orientations of DSA nanopattern arrays were obtained that covered the entire surface of patterned Si substrates, including both trench and mesa regions. The design of DSA sub-layers and guide patterns, such as hardening the sub-layer by photo-crosslinking, nano-structuring on mesas, the relation between trench/mesa width, and BCP equilibrium period, were explored with a view to developing defect-reduced DSA lithography technology.

SUBMITTER: Koh HD

PROVIDER: S-EPMC5509098 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:Augmenting the oriented attachment (OA) crystal growth phenomena, herein, we demonstrate fabrication of ultrathin CuO nanowires from self-assembled one-dimensional (1D) nanowires of Cu(OH)2 nanocrystals. A facile environmentally benign sol-gel approach, which utilizes base-catalyzed hydrolysis followed by directed self-assembly and crystal growth of nanocrystals, is developed to prepare Cu(OH)2 nanowires. The sol of Cu(OH)2 nanocrystals shows aggregative self-assembly guided by the OA crystal growth process to form ultrathin Cu(OH)2 nanowires, with an average length of 675 ± 4 nm and diameter of 6 ± 2 nm. The time-dependent UV-visible spectral traces, along with real-time imaging of nanocrystals self-assembly and growth under the transmission electron microscope, are evidenced the concept of the OA crystal growth directed self-assembly, yielding 1D colloidal nanoarrays of Cu(OH)2. The powder XRD traces collected during the self-assembly and crystal growth process reveal the directional aggregative crystal growth along the facet of [001], confirming the OA directed crystal growth and fusion of nanocrystals to yield 1D nanostructures. The gradual blue-shift in optical absorption maxima from 770 nm in initial precursor solution, to 670 nm for Cu(OH)2 nanocrystals sol, and finally to 647 nm for self-assembled 1D Cu(OH)2 nanowires have further evidenced the formation of Cu(OH)2 nanowires. Upon subjecting self-assembled Cu(OH)2 nanowires for post-annealing treatment, ultrathin CuO nanowires with average length of 7 ± 0.50 μm and diameter of 27 ± 2 nm is obtained in high purity. The experimental powder XRD patterns of Cu(OH)2 and CuO nanowires match the simulated XRD patterns, indexing the crystal unit cell structures to orthorhombic and monoclinic, respectively. The tailored narrow optical band gaps for Cu(OH)2 and CuO nanowires are found to be 1.51 eV and 1.10 eV. The theoretical band gap predicted for Cu(OH)2 nanowires is 1.52 eV and is in good agreement with its optical band gap, whereas theoretical band computed for CuO nanowires is 0.13 eV lower than from its optical band gap.

Dataset Information

Directed Self-Assembly on Photo-Crosslinked Polystyrene Sub-Layers: Nanopattern Uniformity and Orientation.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets