• Journal of the Optical Society of Korea
• /
• v.5 no.1
• /
• pp.9-15
• /
• 2001

The ocean Scanning Multi-spectral Imager (OSMI) is a payload on the KOrea Multi-Purpose SATellite (KOMPSAT) to perform worldwide ocean color monitoring f the study of biological oceanography. OSMI performs solar and dark calibrations for on-orbit instrument calibration. The purpose of the solar calibration is to monitor the degradation of imaging performance for each pixel of 6 spectral bands and to correct the degradation effect on OSMI image during the ground station date processing. The design, the operation concept, and the radiometric characteristics of the solar calibration are investigated. A linear model of image response and a solar calibration radiance model are proposed to study the instrument characteristics using the solar calibration data. The performance of spectral responsivity and spatial response uniformity. The first solar calibration data and the analysis results are important references for further study on the on-orbit stability of OSMI response during its lifetime.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.9 no.1
• /
• pp.51-54
• /
• 2009

Transparent Cuprous oxide film was deposited by rapid thermal oxidation (RTO) of Cu at $500^{\circ}C$/45s condition on textured single-crystal n-Si substrate to form $Cu_2O$/n-Si heterojunction photodiode. The Hall effect measurements for the $Cu_2O$ films showed a p-type conductivity. The photovoltaic and electrical properties of the junction at room temperature were investigated without any post-deposition annealing. I-V characteristics revealed that the junction has good rectifying properties. The C-V data showed abrupt junction and a built-in potential of 1 V. The photodiode showed good stability and high responsivity in the visible at three regions; 525 nm, 625-700 nm, and 750nm denoted as regions A, B, and C, respectively.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.65 no.3
• /
• pp.452-456
• /
• 2016

In this paper, a dual-channel readout amplifier array is realized in a standard $0.18{\mu}m$ CMOS technology for the applications of panoramic scan LADAR systems. Each channel consists of a PIN photodiode with 0.9 A/W responsivity and a 1.0 Gb/s readout amplifier(ROA). The proposed ROA shares the basic configuration of the previously reported feedforward TIA, except that it exploits a replica input to exclude a low pass filter(LPF), thus reducing chip area and improving integration level, and to efficiently reject common-mode noises. Measured results demonstrate that each channel achieves $70dB{\Omega}$ transimpedance gain, 829 MHz bandwidth, -22 dBm sensitivity for $10^{-9}BER$, -34 dB crosstalk between adjacent channels, and 45 mW power dissipation from a single 1.8 V supply.

• Journal of Sensor Science and Technology
• /
• v.17 no.5
• /
• pp.346-349
• /
• 2008

A metal-semiconductor-metal (MSM) ultraviolet (UV) photodetector (PD) is proposed as an effective UV sensing device for integration with a GaN n-channel MISFET on auto-doped p-type GaN grown on a silicon substrate. Due to the high hole barrier of the metal-p-GaN contact, the dark current density of the fabricated MSM PD was less than $3\;nA/cm^2$ at a bias of up to 5 V. Meanwhile, the UV/visible rejection ratio was 400 and the cutoff wavelength of the spectral responsivity was 365 nm. However, the UV/visible ratio was limited by the sub-bandgap response, which was attributed to defectrelated deep traps in the p-GaN layer of the MSM PD. In conclusion, an MSM PD has a high process compatibility with the n-channel GaN Schottky barrier MISFET fabrication process and epitaxy on a silicon substrate.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2009.05a
• /
• pp.388-391
• /
• 2009

In this paper, We observed spectral responsivity of general poly-cristalline silicon solar cell. This is very important to define solar cell's characteristics. So we tested two small modules that made of poly-cristalline silicon solar cells. We expect to the result of this experiment is useful for researching and measuring solar cell's characteristics.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.06a
• /
• pp.367-368
• /
• 2007

To investigate the 2nO thin films which are interested in the next generation of short wavelength LEDs and Lasers and UV photodetector with p-type inversion layer, the ZnO thin films were deposited by RF sputtering system. Gas ratios and work pressure is Ar : $O_2$ = 4 : 1 and 15 mTorr, respectively, and the purity of ZnO target is 5N. The ZnO thin films were deposited at 300, 450, and $650^{\circ}C$. The current-voltage, responsivity and quantum efficiency of devices were studied and compared with each devices.

• Korean Journal of Materials Research
• /
• v.32 no.8
• /
• pp.333-338
• /
• 2022

In this work, we developed silver nanowires and a silicon based Schottky junction and demonstrated ultrafast broadband photosensing behavior. The current device had a response speed that was ultrafast, with a rising time of 36 ㎲ and a falling time of 382 ㎲, and it had a high level of repeatability across a broad spectrum of wavelengths (λ = 365 to 940 nm). Furthermore, it exhibited excellent responsivity of 60 mA/W and a significant detectivity of 3.5 × 10¹² Jones at a λ = 940 nm with an intensity of 0.2 mW cm^-2 under zero bias operating voltage, which reflects a boost of 50 %, by using the AC PV effect. This excellent broadband performance was caused by the photon-induced alternative photocurrent effect, which changed the way the optoelectronics work. This innovative approach will open a second door to the potential design of a broadband ultrafast device for use in cutting-edge optoelectronics.

• Korean Parent-Child Health Journal
• /
• v.5 no.2
• /
• pp.129-144
• /
• 2002

This longitudinal quasi-experimental research was conducted to develop parent role education program and to evaluate the effect of this program for mother-infant interaction, childrearing environment and infant development. The subjects were the healthy infants weighing over 2,500gm at birth, whose gestational age was more than 37weeks, and their healthy mothers. The sample consisted of eighteen mother-infant dyads for intervention group and sixteen dyads for control group. Data were collected from March 15th in 1999 to Jun 20th in 2000. The intervention group received programmed education consisted of discharge education, telephone counselling, and home visiting care. But control group were collected data without programmed education. In this study, the Nursing Child Assessment Teaching Scale(NCATS) devised by Barnard was used to determine the mother-infant interaction, HOME was used to determine the childrearing environment, and Griffiths mental development scale was used to determine the infant development. The data were analyzed using SPSS Win using chi-square test, t-test, and repeated measure ANOVA. This study was focused on the results of twelve months time point. Summaries of the results were as follows: 1. There was no significant difference in mother-infant interaction(NCATS) between intervention group and control group. But both of two groups showed significantly higher in interaction score at twelve months than at six months in the subscales of social-emotional growth fostering, and responsiveness to caregiver. 2. There was no significant difference in childrearing environment(HOME) between two groups at twelve months. But when each subscale of HOME was examined, intervention group showed higher scores in the dimensions of maternal involvement with child(p=.001), and maternal emotional-verbal responsivity(p=.048). 3. There was no significant difference in GQ of the Griffiths mental development scale between two groups, although significant difference was found in performance subscale. 4. Infant development at twelve months showed significant correlation with mother-infant interaction and childrearing environment at six months, although mother-infant interaction and childrearing environment at twelve months did not show significant correlations with infant development at twelve months. 5. Developmental scores at six months showed significant correlations with variety in daily stimulation, and mother's emotional, verbal responsivity, whereas developmental scores at twelve months showed significant correlations with acceptance of child behavior at six months, and appropriate play material at twelve months. In conclusion, the maternal education program for primipara showed long term effect in some categories in organizing the childrearing environment, and fostering the infant development. We suggest further study and implications of parent role education program for high risk parents such as parents in low economic status or with premature babies.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.39 no.12
• /
• pp.1008-1015
• /
• 2002

The fabricated La-modified lead titanate (PLT) thin film without poling treatment was investigated for modulation frequency dependence of pyroelectric properties by the dynamic method. $Pb_{l-x}La_{x}Ti_{l-x/4}O_3$(x=0.1) (PLT(10)) thin film haying 10 mol% La content was deposited on a Pt/$TiO_{x}$/$SiO_2$/Si substrate by sol-gel method. The PLT(10) thin film exhibits a relatively excellent dielectric property. The pyroelectric coefficient (p) of the PLT(10) thin film is 6.6 x $10^{-9}C$$textrm{cm}^2$$.$K without frequency dependence. The figure of merits for the voltage responsivity and specific detectivity are 1.03 x $10^{-11}C$.cm/J and 1.46 x $10^{-10}C$.cm/J, respectively The PLT(10) thin film has voltage responsivity (RV) of 5.IS V/W at 8 Hz. Noise equivalent power (NEP) and specific detectivity ($D^{*}$) of the PLT(10) thin film are 9.93 x $10^{-8}$W/$Hz^{1/2}$ and 1.81 x $10^{6}$cm.$Hz^{1/2}$/W at the same frequency of 100 Hz,, respectively The results means that PLT thin film having 10 mol% La content is suitable for the sensing materials of pyroelectric IR sensors.

• Korean Journal of Optics and Photonics
• /
• v.10 no.6
• /
• pp.500-506
• /
• 1999

We designed and fabricated a bidirectional optical transceiver module for low cost access network. An integrated chip forming a pin-PD on an 1.3 urn FP-LD was assembled by flip-chip bonding on a Si optical bench, a single mode fiber with an angled end facet was aligned passively with the integrated chip on V-groove of Si-optical bench. Gaussian beam theory was applied to evaluate the coupling coefficients as a function of some parameters such as alignment distance, angle of fiber end facet, vertical alignment error. The theory is also used to search the bottle-neck between transmittance and receiving coupling efficiency in the bi-directional optical system. Tn this paper, we confirmed that reduction of coupling efficiency by the vertical alignment error between laser beam and fiber core axis can be compensated by controlling the fiber facet angle. In the fabrication of sub-module, a'||'&'||' we made such that the fiber facet have a corn shape with an angled facet only core part, the reflection of transmitted laser beam from the fiber facet could be minimized below -35 dE in alignment distance of 2: 30 /J.m. In the same condition, transmitted output power of -12.1 dEm and responsivity of 0.2. AIW were obtained.