Self-Assembled Nanodot Fabrication by Using Diblock Copolymer

In this study, we investigate self-assembled large-area nanodot fabrication on a silicon substrate using poly(styrene)-poly(dimethyl-siloxane) (PS-PDMS) for the application to quantum dot solar cell. By optimizing the PS-PDMS concentration by 2% and the volume of PS-PDMS solutions by 20 μL/cm2 dropped to silicon substrate, nanodots with a pitch size of 33 nm and a diameter of 23 nm are achieved with the molecular weight of 30,000-7,500. It is found that the dropped volume of PS-PDMS solution correlated to the thickness of spin-coated PS-PDMS layer has a great effect on the size and the pattern morphology.

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Assembly of CdSe onto mesoporous TiO2 films induced by a self-assembled monolayer for quantum dot-sensitized solar cell applications

Journal of Power Sources ◽

10.1016/j.jpowsour.2010.01.044 ◽

2010 ◽

Vol 195 (15) ◽

pp. 5109-5113 ◽

Cited By ~ 99

Author(s):

Lai-Wan Chong ◽

Huei-Ting Chien ◽

Yuh-Lang Lee

Keyword(s):

Solar Cell ◽

Quantum Dot ◽

Mesoporous Tio2 ◽

Tio2 Films ◽

Self Assembled Monolayer ◽

Mesoporous Tio2 Films ◽

Self Assembled

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Formation of 12-nm Nanodot Pattern by Block Copolymer Self-Assembly Technique

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.497.122 ◽

2011 ◽

Vol 497 ◽

pp. 122-126 ◽

Cited By ~ 4

Author(s):

Miftakhul Huda ◽

Takuro Tamura ◽

You Yin ◽

Sumio Hosaka

Keyword(s):

Molecular Weight ◽

Quantum Dot ◽

Self Assembly ◽

Microphase Separation ◽

Experimental Result ◽

Storage Device ◽

Pdms Layer ◽

Pdms Film ◽

Assembly Technique ◽

Total Molecular Weight

In this work, we studied the fabrication of 12-nm-size nanodot pattern by self-assembly technique using high-etching-selectivity poly (styrene)-poly (dimethyl-siloxane) (PS-PDMS) block copolymers. The necessary etching duration for removing the very thin top PDMS layer is unexpectedly longer when the used molecular weight of PS-PDMS is 13.5-4.0 kg/mol (17.5 kg/mol total molecular weight) than that of 30.0-7.5 kg/mol (37.5 kg/mol total molecular weight). From this experimental result, it was clear that PS-PDMS with lower molecular weight forms thicker PDMS layer on the air/polymer interface of PS-PDMS film after microphase separation process. The 22-nm pitch of nanodot pattern by self-assembly holds the promise for the low-cost and high-throughput fabrication of 1.3 Tbit/inch2storage device. Nanodot size of 12 nm also further enhances the quantum-dot effect in quantum-dot solar cell.

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Investigation of Diblock Copolymer thin film Morphology for Nanolithography

MRS Proceedings ◽

10.1557/proc-461-179 ◽

1996 ◽

Vol 461 ◽

Cited By ~ 6

Author(s):

Miri Park ◽

Christopher Harrison ◽

Paul M. Chaikin ◽

Richard A. Register ◽

Douglas Adamson ◽

...

Keyword(s):

Thin Films ◽

Silicon Nitride ◽

Diblock Copolymer ◽

Diblock Copolymers ◽

Microphase Separation ◽

Large Area ◽

Etching Technique ◽

Copolymer Films ◽

Self Assembled ◽

Self Assembled Layer

ABSTRACTThe microphase separated morphology of diblock copolymers can be used to generate well-ordered nanometer scale patterns over a large area. To achieve this goal, it is important to understand and control the behavior of diblock copolymer thin films on substrates, which can differ from the bulk behavior. We have investigated the morphologies and ordering in thin polystyrene-polybutadiene (PS-PB) diblock copolymer films on bare silicon and silicon nitride substrates, and also on polymethylmethacrylate (PMMA) coated substrates. The PS-PB copolymers are synthesized to form, in bulk, PB cylinders or spheres in a PS matrix. In thin films (10–60 nm thick), prepared by spin-coating, we observe that the morphology and ordering of the microdomains are affected by strong wetting constraints and a reduced chain mobility on the substrate. The thinnest self-assembled layer of the copolymer films shows no in-plane microphase separation on both types of substrates. The PS blocks wet the PMMA substrates whereas the PB blocks wet the bare substrates as well as the air interface. Hence, different film thicknesses are necessary on the two types of substrates to obtain a uniform film of the first self-assembled cylindrical or spherical microdomain layer. The first layer of the cylindrical copolymer can vary from cylindrical to spherical morphology with a few nanometer decrease in film thickness. In the case of spherical PS-PB diblock copolymer films, we observe that the ordering of the microdomains is improved in the films on the PMMA substrates, compared to those on the bare substrates. We also demonstrate a successful transfer of the microdomain patterns to silicon nitride substrates by a reactive ion etching technique.

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Fabrication and Unique Optical Properties of Two-Dimensional Silver Nanorod Arrays with Nanometer Gaps on a Silicon Substrate from a Self-Assembled Template of Diblock Copolymer

Langmuir ◽

10.1021/acs.langmuir.6b02934 ◽

2016 ◽

Vol 32 (47) ◽

pp. 12504-12510 ◽

Cited By ~ 3

Author(s):

Shigenori Fujikawa ◽

Mari Koizumi ◽

Akiko Taino ◽

Koichi Okamoto

Keyword(s):

Optical Properties ◽

Diblock Copolymer ◽

Silicon Substrate ◽

Two Dimensional ◽

Nanorod Arrays ◽

Self Assembled

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Self-Assembled Ag Nanocomposites into Ultra-Sensitive and Reproducible Large-Area SERS-Active Opaque Substrates

Nanomaterials ◽

10.3390/nano11082055 ◽

2021 ◽

Vol 11 (8) ◽

pp. 2055

Author(s):

Abeer Fahes ◽

Aotmane En En Naciri ◽

Mohammad Navvabpour ◽

Safi Jradi ◽

Suzanna Akil

Keyword(s):

Silicon Substrate ◽

Large Scale ◽

Low Cost ◽

Photonic Devices ◽

Optical Analysis ◽

Large Area ◽

Pmma Layer ◽

High Throughput Technology ◽

Doped Silicon ◽

Self Assembled

This work describes a novel, one-shot strategy to fabricate ultrasensitive SERS sensors based on silver/poly(methyl methacrylate) (PMMA) nanocomposites. Upon spin coating of a dispersion of PMMA and silver precursor on N-doped silicon substrate, closely separated silver nanoparticles were self-assembled into uniform nanospheres. As a result, a thin hydrophobic PMMA layer embedded with Ag nanoparticles (AgNPs) was obtained on the whole silicon substrate. Consequently, a large-scale, reproducible SERS platform was produced through a rapid, simple, low-cost, and high-throughput technology. In addition, reproducible SERS features and high SERS enhancement factors were determined (SEF ~1015). This finding matches the highest SEF reported in literature to date (1014) for silver aggregates. The potential and novelty of this synthesis is that no reducing agent or copolymer was used, nor was any preliminary functionalization of the surface carried out. In addition, the AgNPs were fabricated directly on the substrate’s surface; consequently, there was no need for polymer etching. Then, the synthetic method was successfully applied to prepare opaque SERS platforms. Opaque surfaces are needed in photonic devices because of the absence of secondary back reflection, which makes optical analysis and applications easier.

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