Fabrication and optical characterization of full color stop band based on rugate-structured porous silicon

Um, Sungyong; Yang, Jum-Hong; Choi, Tae-Eun; Cho, Hyeon; Jin, Sung-Chul; Sohn, Honglae

doi:10.1016/j.mee.2011.03.143

Cited by 6 publications

(4 citation statements)

References 15 publications

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“…15 The pores with artificially controlled morphology such as double layer, Bragg stack, microcavity and rugate structures have been achieved through tuning the waveforms of pulse current. [138][139][140][141][142][143][144][145][146][147][148][149][150][151][152] Fig. 5a-d show cross-section SEM images of p-type pSi prepared by four different kinds of pulse current-voltage waveforms.…”

Section: Vertical Patterningmentioning

confidence: 99%

Electrochemical engineering of hollow nanoarchitectures: pulse/step anodization (Si, Al, Ti) and their applications

et al. 2014

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Hollow nanoarchitectured materials with straight channels play a crucial role in the fields of renewable energy, environment and biotechnology due to their one-dimensional morphology and extraordinary properties. The current challenge is the difficulty on tailoring hollow nanoarchitectures with well-controlled morphology at a relatively low cost. As a conventional technique, electrochemistry exhibits its unique advantage on machining nanostructures. In this review, we present the progress of electrochemistry as a valuable tool in construction of novel hollow nanoarchitectures through pulse/step anodization, such as surface pre-texturing, modulated, branched and multilayered pore architectures, and free-standing membranes. Basic principles for electrochemical engineering of mono- or multi-ordered nanostructures as well as free-standing membranes are extracted from specific examples (i.e. porous silicon, aluminum and titanium oxide). The potential of such nanoarchitectures are further demonstrated for the applications of photovoltaics, water splitting, organic degradation, nanostructure templates, biosensors and drug release. The electrochemical techniques provide a powerful approach to produce nanostructures with morphological complexity, which could have far-reaching implications in the design of future nanoscale systems.

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Section: Vertical Patterningmentioning

confidence: 99%

Electrochemical engineering of hollow nanoarchitectures: pulse/step anodization (Si, Al, Ti) and their applications

et al. 2014

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“…19 Effective refractive index of rugate PS depends directly on porosity. The rugate PS prepared with a sine etching current profile possess a sinusoidally varying porosity gradient in the direction perpendicular to the plane of the filter.…”

Section: Resultsmentioning

confidence: 99%

“…18 To encode multiple rugate structures, three sine waves are summed together to create the composite waveform, which is used as an electrochemical etching current profile. 19 Therefore, multiple rugate PS might have a complex wave-formed porosity gradient rather than a simple porosity of cylindrical macro-pores in the direction perpendicular to the plane of the filter due to the sum of sine components. This complex wave-formed porosity used in the present work should give a distinct pore adsorption and desorption characteristics for sensing applications.…”

Section: Resultsmentioning

confidence: 99%

Fabrication and Optical Characterization of Multi-Encoded Rugate Porous Silicon/Polymer Composite

Cho¹,

Lee²,

Woo³

et al. 2014

j nanosci nanotechnol

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Multi-encoded rugate porous silicon (MRPS)/polystyrene composite films were fabricated by using a free-standing multi-encoded rugate PS and polystyrene. MRPS exhibiting three reflection resonances was generated by an electrochemical etching of silicon wafer using a composite waveform summed three computer-generated pseudo-sinusoidal current waveforms, which were corresponded to the each of the sine components varied from 0.40, 0.38, to 0.36 Hz, with a spacing of 0.02 Hz between each sine component. They displayed three sharp photonic reflection resonances in the optical reflectivity spectrum. MRPS/polymer composite films obtained by casting of polystyrene polymer solution exhibited excellent photonic characteristics and robust structure upon flexing. For a possible application as VOCs sensor, these films were served for the detection of organic vapors such hexane and methanol.

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“…Moreover, study shows that the intensity of UV emission is higher for PS compared to Si, indicating that there is an improvement of the crystallinity of ZnO nanostructures due to free exciton emission [18]. In recent years, PS-based optical devices are widely used for photonic design, benefited from the easy preparation of PS by periodically altering etching time and etching current [19][20][21][22][23][24][25]. Among the photonic structures, porous silicon microcavity (PSM) attracts great interests of many scientists due to its interesting optical properties such as high reflectivity stop band with a sharp reflectance dip in the center of reflectance spectrum.…”

Section: Introductionmentioning

confidence: 99%

Application of porous silicon microcavity to enhance photoluminescence of ZnO/PS nanocomposites in UV light emission

Zhang

Jia

2017

Optik

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This paper presents ZnO nanostructures deposited on porous silicon (PS) and porous silicon microcavity (PSM) substrates by sol-gel method. The effects of annealing temperature and mass ration of zinc acetate to PVA on microstructure, and optical properties of ZnO/PS and ZnO/PSM nanocomposites were systematically investigated by field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) and photoluminescence (PL) spectroscopy. The XRD analysis confirmed that the ZnO/PS nanocomposite preferred strongly to (002) phase orientation. The PL spectra showed that there was a sharp and highly intense UV emission peak located at about 400 nm when annealing temperature was 800 o C for 30 min and the mass ratio of zinc acetate to PVA was 4:1. The detail cross-section FESEM images of ZnO/PSM showed that ZnO nanoparticles uniformly penetrated into all PS layers and adhered to them very well. Furthermore, ZnO/PSM nanocomposites showed relatively stronger UV emissions at around 400 nm compared to the PL spectra of ZnO/PS nanocomposites, that means one-dimension phonic crystal PSM can enhance the PL intensity of ZnO. Such a method may provide an interesting way to develop a new type of UV optoelectronic devices.

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Fabrication and optical characterization of full color stop band based on rugate-structured porous silicon

Cited by 6 publications

References 15 publications

Electrochemical engineering of hollow nanoarchitectures: pulse/step anodization (Si, Al, Ti) and their applications

Electrochemical engineering of hollow nanoarchitectures: pulse/step anodization (Si, Al, Ti) and their applications

Fabrication and Optical Characterization of Multi-Encoded Rugate Porous Silicon/Polymer Composite

Application of porous silicon microcavity to enhance photoluminescence of ZnO/PS nanocomposites in UV light emission

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