• Journal of Integrative Natural Science
• /
• v.2 no.3
• /
• pp.211-214
• /
• 2009

A new porous silicon (PSi) microcavity sensor for the detection of volatile organic compounds (VOCs) was developed. PSi microcavity sensor exhibiting unique reflectivity was successfully obtained by an electrochemical etching of silicon wafer. When PSi was fabricated into a structure consisting of two high reflectivity muktilayer mirrors separated by an active layer, a microcavity was formed. This PSi microcavity is very sensitive structures. Reflection spectrum of PSi microcavity indicated that the full-width at half-maximum (FWHM) was of 10 nm and much narrower than that of fluorescent organic molecules or quantum dot. The detection of volatile organic compounds (VOCs) using PSi microcavity was achieved. When the vapor of VOCs condensed in the nanopores, the refractive indices of entire particle increased. When PSi microcavity was exposed to acetone, ether, and toluene, PSi microcavity in reflectivity was red shifted by 28 nm, 33 nm, and 20 nm for 2 sec, respectively.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.26 no.5
• /
• pp.391-396
• /
• 2013

Recently, microcavity is studied to reduce the optical loss of BLU and OLED. In this paper, we suggest applying microcavity to photo-luminescent lamp with plasma discharge technology to meet the display applications for a BLU for LCD. The structure of photo-luminescent lamp consists of SUS foil and ITO glass with microcavity. The opto-electric characteristics of photo-luminescent lamp with microcavity was evaluated. The brightness of photo-luminescent device was increased over $111cd/m^2$ with the adaptation of patterned microcavity at $30{\mu}m$. The 3D optical simulation verified the enhanced light outcoupling when microcavity applied to the device.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.19 no.6
• /
• pp.293-297
• /
• 2009

In this paper, we made three kinds of porous silicon samples (single layer, distributed Bragg reflector, and microcavity) by electrochemical etching p-type silicon substrate. And then, we investigated their reflectance spectrum properties. We found that the number of fringe patterns and the maximum reflectivity of porous silicon multilayer increased compared with a porous silicon sinlge layer. In addition, we can observe that the DBR (distributed Bragg reflector) porous silicon has a full-width at half-maximum about 33 nm which is narrower than the porous silicon single layer and porous silicon microcavity.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2007.08b
• /
• pp.1440-1442
• /
• 2007

In this work, we have modeled and fabricated microcavity-enhanced OLED using the 1-dimensional distributed Bragg reflector model (DBR). Results show that simulated spectrum intensity of microcavity OLED increased more than 30% compared to the conventional OLED, by use of DBR with $TiO_2$ and $SiO_2$. Spectral change of green and blue emission was expected to give the deeper color. The experimental design and characterization as well as the matching with simulated properties were performed for microcavity OLED for actual application.

• Proceedings of the Optical Society of Korea Conference
• /
• 1999.08a
• /
• pp.184-185
• /
• 1999

• Proceedings of the Optical Society of Korea Conference
• /
• 2006.07a
• /
• pp.239-240
• /
• 2006

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.24 no.1
• /
• pp.32-35
• /
• 2011

Top-emission device has a merit of high aperture ratio and narrow emission spectrum compared to that of bottom-emission one. Emission spectra of top-emission organic light-emitting diodes depending on a layer thickness and view angle were analyzed using a theory of microcavity. Device structure was manufactured to be Al (100 nm)/TPD/$Alq_3$/LiF (0.5 nm)/Al (2 nm)/Ag (30 nm). N,N'-diphenyl-N,N'- di (m-tolyl)-benzidine (TPD) and tris (8-hydroxyquinoline) aluminium (Alq3) were used as a hole-transport layer and emission layer, respectively. And a thickness of TPD and Alq3 layer was varied in a range of 40 nm~70 nm and 60 nm~110 nm, respectively. Angle-dependent emission spectrum out of the device was measured with a device fixed on a rotating plate. Since the top-emission device has a property of microcavity, it was observed that the emission spectrum shift to a longer wavelength region as the organic layer thickness increases, and to a shorter wavelength region as the view angle increases. Layer thickness and view-angle dependent emission spectra of the device were analyzed in terms of microcavity theory. A reflectivity of semitransparent cathode and optical path length were deduced.

• Journal of the Optical Society of Korea
• /
• v.17 no.5
• /
• pp.423-427
• /
• 2013

We present the preparation and characteristics of liquid-phase sensors based on nano-porous silicon multilayer structures for determination of organic content in gasoline. The principle of the sensor is a determination of the cavity-resonant wavelength shift caused by refractive index change of the nano-porous silicon multilayer cavity due to the interaction with liquids. We use the transfer matrix method (TMM) for the design and prediction of characteristics of microcavity sensors based on nano-porous silicon multilayer structures. The preparation process of the nano-porous silicon microcavity is based on electrochemical etching of single-crystal silicon substrates, which can exactly control the porosity and thickness of the porous silicon layers. The basic characteristics of sensors obtained by experimental measurements of the different liquids with known refractive indices are in good agreement with simulation calculations. The reversibility of liquid-phase sensors is confirmed by fast complete evaporation of organic solvents using a low vacuum pump. The nano-porous silicon microcavity sensors can be used to determine different kinds of organic fuel mixtures such as bio-fuel (E5), A92 added ethanol and methanol of different concentrations up to 15%.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2006.08a
• /
• pp.473-476
• /
• 2006

Microcavity plasma devices having characteristic dimensions below $100\;{\mu}m$ have been investigated as a candidate for the next generation of plasma displays. Arrays of inverted pyramid microcavity devices, fabricated in Si with emitting apertures of $(50\;{\mu}m)^2$ and designed for AC or bipolar excitation, demonstrate a luminous efficacy above 6 lm/W at pressures up to and beyond one atmosphere of Ne/Xe mixtures. Also the design of analogous microplasma devices in ceramic multilayer structures or plastic substrates is disccussed.

• Bulletin of the Korean Chemical Society
• /
• v.26 no.9
• /
• pp.1344-1346
• /
• 2005

We report microcavity effect of top emission organic light-emitting diodes (OLEDs) by using Al cathode and anode, which are feasible for not only top emission EL and angle dependant effects but facile evaporation process without ion sputtering. The device in case of $Alq_3$ green emission showed largely shifted EL maximum wavelength as 650 nm maximum emission. It was also observed that detection angle causes different EL maximum wavelength and different CIE values in R, G, B color emission. As a result, the green device using $Alq_3$ emission showed 650 nm emission ($0^{\circ}$) to 576 nm emission ($90^{\circ}$) as detection angle changed. We believe that these phenomena can be also explained with microcavity effect which depends on the different length of light path caused by detection angle.