Organic Light-Emitting Microdevices Fabricated by Nanoimprinting Technology Using Diamond Molds

Kiyohara, Shuji; Fujiwara, M.; Matsubayashi, Fumio; Mori, Katsumi

doi:10.1143/jjap.44.3686

Cited by 8 publications

(4 citation statements)

References 13 publications

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“…During the last decade, organic light-emitting diodes (OLEDs) have been extensively studied by the international scientific community [1,2,3,4]. This kind of device has attracted great interest due to their adjustable optical and electrical properties [5,6], mechanical flexibility [7,8], low cost [8], and simple manufacturing processes [9].…”

Section: Introductionmentioning

confidence: 99%

Expanded Electroluminescence in High Load CdS Nanocrystals PVK-Based LEDs

et al. 2019

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Immiscibility between dimethyl sulfoxide (DMSO) and polar solvents used for poly(N-vinylcarbazole) (PVK) solutions, leads to failed light-emitting diodes when colloidal cadmium sulfide (CdS) nanoparticles capped with thiophenol are incorporated to their active layer. To prevent this, a heat treatment is applied to the CdS nanoparticles in order to evaporate DMSO solvent. After evaporation most of the nanoparticles increased their size, and some of them show hexagonal crystalline structure instead of the original cubic zinc-blende observed in colloidal pre-treated nanoparticles. Nevertheless, enhanced electronic properties are measured in light-emitting devices when DMSO-free nanoparticles are embedded in the poly(N-vinylcarbazole) active layer. Light emission from these hybrid devices comprises the whole visible range of wavelengths as searched for white LEDs. Moreover, electroluminescence from both types of CdS nanoparticles (smaller cubic and bigger hexagonal) has been discriminated and interpreted through Gaussian deconvolution.

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Section: Introductionmentioning

confidence: 99%

Expanded Electroluminescence in High Load CdS Nanocrystals PVK-Based LEDs

et al. 2019

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“…The diamond mold has a lifetime about 100 times longer than that of silicon dioxide (SiO 2 ) mold or that of silicon (Si) mold, both using a conventional NIL process. The reason for the longer lifetime is that diamond has many unique properties such as hardness, high thermal conductivity and low thermal expansion [1][2][3]. The diamond mold has been fabricated by radio frequency (RF) oxygen plasma with Bi 4 Ti 3 O 12 octylate mask in the electron beam (EB) lithography technology that we developed [4,5].…”

Section: Introductionmentioning

confidence: 99%

Nanofabrication of Three-Dimensional Imprint Diamond Molds by ECR Oxygen Ion Beams Using Polysiloxane

Kiyohara

Kashiwagi

Takikawa

et al. 2009

e-J. Surf. Sci. Nanotechnol.

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We have investigated the nanofabrication of three-dimensional (3D) chemical vapor deposited (CVD) diamond molds in Electron Cyclotron Resonance (ECR) oxygen ion beam etching technologies using polysiloxane n as an electron beam (EB) mask and a room-temperature (RT)-imprint resist material. The polysiloxane exhibited a negative-exposure characteristic and its sensitivity was 5.5 × 10 −5 C/cm 2 . The maximum etching selectivity of polysiloxane film against diamond film was 4.7, which was obtained under the following ECR oxygen ion etching conditions: ion energy of 400 eV, ion incidence angle of 0• , microwave power of 100 W, gas pressure of 1.4 × 10Pa and stage temperature of 24 • C. The diamond molds of cone and tetragonal pyramid dots were fabricated with polysiloxane mask in EB lithography technology using the RT-nanoimprint lithography (NIL) process. The dots are 500, 600, 700, 800, 900 nm in diameter and width respectively. The pitch between the dots is 2 µm, and each dot has a height of about 1 µm. It was found that the optimum imprinting pressure and its depth obtained after the press for 5 min were 0.5 MPa and 0.5 µm respectively. The resulting diameter of each imprinted polysiloxane pattern was in good agreement with that of the 3D-diamond mold. We carried out the RT-NIL process for the fabrication of diamond nanopatterns, using the 3D-diamond molds that we developed.

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“…Some of the common gratings or microlenses are also used for LEDs or OLEDs as antireflective structures. [17]- [25] When light goes from a structure with low refractive index to one with high refractive index, the reflection can be reduced by the structure, making the structure useful for solar cell panels [26], [27] or the front panel of displays. [28] For the use of antireflection, subwavelength structures were fabricated by Kanamori et al, [5], [29] and Kasugai et al [30] .…”

Section: Introductionmentioning

confidence: 99%

Design of a wavelength independent grating in the resonance domain

et al. 2007

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We propose using blazed gratings in the resonance domain with period larger than the wavelength for anti-reflection and polarization selection. The inherent problem in this region is wavelength dispersion, which is solved by analyzing the total reflectivity and electric field distribution. The positional relationship between the area of strong electric field, and the side and tip of the grating is crucial to the wavelength dispersion of total reflectivity.

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Organic Light-Emitting Microdevices Fabricated by Nanoimprinting Technology Using Diamond Molds

Cited by 8 publications

References 13 publications

Expanded Electroluminescence in High Load CdS Nanocrystals PVK-Based LEDs

Expanded Electroluminescence in High Load CdS Nanocrystals PVK-Based LEDs

Nanofabrication of Three-Dimensional Imprint Diamond Molds by ECR Oxygen Ion Beams Using Polysiloxane

Design of a wavelength independent grating in the resonance domain

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