• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
• /
• pp.163.1-163.1
• /
• 2016

Lead halide perovskites CH3NH3PbX3 (X=Cl, Br, I) have received great interest in the past few years because of their excellent photoelectronic properties as well as their low-cost solution process. Their theoretical efficiency limit of the solar cell devices was predicted around 31% by a detailed balance model for the reason that exceptional light-harvesting and superior carrier transport properties. Additionally, these excellent properties contribute to the applications of optoelectronic devices such as LASERs, LEDs, and photodetectors. Since these devices are mainly using perovskite thin film, one of the most important factor to decide the efficiency of these applications is the quality of the film. Even though, optoelectrical devices are composed of polycrystalline thin film in general, not a single crystalline form which has longer carrier diffusion length and lower trap density. For these reasons, monodomain perovskite thin films have potential to elicit an optimized device efficiency. In this study, we analyzed the crystallography of the in-plane aligned perovskite thin film by X-ray diffraction (XRD) and selected area electron diffraction (SAED). Also the basic optic properties of perovskites were checked using scanning electron microscopy (SEM) and UV-Vis spectrum. From this work, the perovskite which is aligned in all directions both of out-of-plane and in-plane was fabricated and analyzed.

• 한국재료학회지
• /
• 제19권9호
• /
• pp.499-503
• /
• 2009

Transparent ITO films were deposited on a polycarbonate substrate with RF magnetron sputtering in a pure argon (Ar) and oxygen ($O_2$) gas atmosphere, and then post deposition electro annealed for 20 minutes in a $4{\times}10^{-1}$ Pa vacuum. Electron bombardment with an accelerating voltage of 100 V increased the substrate temperature to $120^{\circ}C$. XRD analysis of the deposited ITO films did not show any diffraction peaks, while electro annealed films indicated the growth of crystallites on the (211), (222), and (400) planes. The sheet resistance of ITO films decreased from 103 to $82{\Omega}/\square$. The optical transmittance of ITO films in the visible wavelength region increased from 85 to 87%. Observation of the work function demonstrated that the electro-annealing increased the work function of ITO films from 4.4 to 4.6 eV. The electro annealed films demonstrated a larger figure of merit of $3.0{\times}10^{-3}{\Omega}^{-1}$ than that of as deposited films. Therefore, the electro annealed films had better optoelectrical performances than as deposited ITO films.

• 한국섬유공학회:학술대회논문집
• /
• 한국섬유공학회 2003년도 The Korea-Japan Joint Symposium
• /
• pp.77-78
• /
• 2003

The surface evenness and texture of textile products are closely related with the irregularity of yarn thickness which has an important role to influence the quality and the process efficiency. For measuring yam thickness the capacitive method is known to dominate the market, delivering results that are in a close relation with the mechanical properties of yarn, while the optical method offers information that seems related rather with the apparent quality of yarn. If a thin light beam is applied for the optoelectrical measurement, it is very possible that this method can provide us with important information which is not obtainable from the capacitive type measurement. This paper reports the results of a study about the yarn thickness and its variation on the basis of a new measurement system using a laser slit beam. Analysis of the new system confirms that we can extract new information on the yarn irregularity ranging into much short wavelengths. Even the visual shade created by the yam doubling and twisting can be measured and represented well. Depending on the yam types, the thickness measurements show their own characteristics.

• Transactions on Electrical and Electronic Materials
• /
• 제10권5호
• /
• pp.169-172
• /
• 2009

The ZnO/CuSn/ZnO (ZCSZ) multilayer films were deposited on polycarbonate substrates using reactive RF and DC magnetron sputtering. The thickness of each layer was 50 nm/5 nm/45 nm, respectively. The ZCSZ films showed a sheet resistance of $44{\Omega}$/Sq, which was an order of magnitude lower than that indium tin oxide (ITO) films. Although the ZCSZ films had a CuSn interlayer that absorbed visible light, both films had similar optical transmittances of 74% in the visible wavelength region. The figure of merit of the ZCSZ films was $1.0{\times}10^{-3}{\Omega}^{-1}$ and was greater than the value of the ITO films, $1.6{\times}10^{-4}{\Omega}^{-1}$. From the X-ray diffraction (XRD) analysis, the ITO films did not show any diffraction peaks, whereas the ZCSZ films showed diffraction peaks for the ZnO (100) and (002) phases. The hardness of the ITO and ZCSZ films were 5.8 and 7.1 GPa, respectively, which were determined using nano-indentation. From these results, the ZCSZ films exhibited greater optoelectrical performance and hardness compared to the conventional ITO films.

• 한국광학회지
• /
• 제17권1호
• /
• pp.31-37
• /
• 2006

본 논문에서는 컴퓨터 형성 홀로그램을 이용하여 디지털 데이터의 저작권을 보호할 수 있는 워터마킹 방법을 제안하였다. 제안된 방법에서는 제작된 컴퓨터 형성 홀로그램으로부터 분리된 두개의 위상 변조된 무작위패턴 생성시켜 하나는 원 영상에 삽입될 워터마크 영상으로 사용하고 다른 하나는 워터마킹 된 영상에서 워터마크 영상을 추출하기 위한 디코딩 키로 사용된다. 워터마킹 된 영상의 제작과정은 수치 해석적으로 수행하고 워터마크 영상은 광학적인 방법으로 추출한다. 제안된 방법은 워터마킹 된 영상이 절단에 대해서 강인함을 컴퓨터 모의실험을 통해 확인하였고, 위상변조 특성이 있는 액정 광변조기를 이용하여 광학적으로 구현하였다.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2004년도 춘계학술대회 논문집 반도체 재료 센서 박막재료 전자세라믹스
• /
• pp.46-50
• /
• 2004

인쇄/소결 방법으로 가시영역에서 광감도가 매우 큰 CdSSe 다결정 후막을 만들고 이를 이용하여 광전도 젤을 제작하였다. 후막의 낱알 크기는 $5{\mu}m$ 정도이였다. 광전도 셀은 소결 촉진제로 첨가한 $cucl_2$ 양이 CdSSe 1 g 당 3.06~0.10 mg 정도이변 감도, 광전류와 암전류의 비율이 각각 0.7과 $10^5$ 이상을 나타내었고, Cds 와 CdSe 의 질량비가 1:0, 9:1, 8:2, 7:3, 6:4, 5:5일 때 응답파장은 각각 500nm, 520nm, 540nm, 570nm, 620nm, 660nm였다. 또한 주파수 특성을 나타내는 응답시간은 오름시간과 감쇠시간이 각각 30관 20ms 정도 이였으며 최대허용 소비 전력은 80mw 이상이었다. 이상과 같이 인쇄/소결 방법으로 제작된 광전도 셀은 $cucl_2$ 양이 CdSSe 1g 당 0.06~0.10 mg 정도 주입되면 센서로써 좋은 특성을 나타내었다.

• 반도체디스플레이기술학회지
• /
• 제15권2호
• /
• pp.11-15
• /
• 2016

This paper, Ga-doped ZnO (GZO) thin films which were deposited on Corning glass substrate using an magnetron sputtering deposition technology and then the post deposition annealing process was conducted for 30 minutes at different temperature of 100, 200, 300, and $400^{\circ}C$, respectively. So as to investigate the properties for the relevant the Concentration and Oxygen Vacancy with Annealing temperature of Ga-doped ZnO thin films by RF Sputtering method. The Carrier concentration is enhanced as annealing temperature decreases, and also the oxygen vacancy concentration is enhanced as annealing temperature decreased. Oxygen vacancy will decrease along with Carrier concentration. This change in Carrier concentration is related to changes in oxygen vacancy concentration. The figure of merit obtained in this study means that Ga-doped ZnO films which annealed at $400^{\circ}C$ have the lowest Carrier concentration and Oxygen vacancy, which have the highest optoelectrical performance that it could be used as a transparent electrode.

• 반도체디스플레이기술학회지
• /
• 제15권4호
• /
• pp.41-45
• /
• 2016

ITO/GZO double layered thin films were prepared on transparent glass substrates. Ga-doped ZnO(GZO) films were deposited by RF magnetron sputtering using an ZnO:Ga (98: 2 wt%) target. The post deposition annealing process was conducted for 30 minutes at different temperature of 100, 200, 300 and $400^{\circ}C$, respectively. As increase annealing temperature, ITO/GZO double layered thin films show the increment of the prefer orientation of ZnO diffraction peak (002) in the XRD patterns. We obtained Ga-doped ZnO thin films with a lowest resistivity of $1.84{\times}10^{-4}{\Omega}-cm$ at $400^{\circ}C$ and transparency above 80% in visible ranges. The figure of merit obtained in this study means that ITO/GZO double layered thin films which annealed at $400^{\circ}C$ have the highest optoelectrical performance in this study.

• 전기학회논문지
• /
• 제60권1호
• /
• pp.105-108
• /
• 2011

Newly-developed fabrication of a p-n heterojunction diode constructed with a p-Si nanowire (NW) and an n-ZnO nanoparticle (NP) thin-film by the dielectrophoresis (DEP) technique is demonstrated in this study. With the bias of 20 Vp-p at the input frequency of 1 MHz, the most efficient assembly of the n-ZnO NPs is shown for the fabrication of the p-n heterojunction diode with a p-Si NW. The p-n heterojunction diode fabricated in this study represents current rectifying characteristics with the turn on voltage of 1.1 V. The diode can be applied to the fabrication of optoelectrical devices such as photodetectors, light-emitting diodes (LEDs), or solar cells based on the high conductivity of the NW and the high surface to volume ratio of the NP thin film.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
• /
• pp.304-308
• /
• 2004

The $Cd_{1-x}Zn_xS$ thin films were grown on the Si(100) wafers by a hot wall epitaxy method(HWE). The source and substrate temperature are $600^{\circ}C\;and\;440^{\circ}C$ respectively. The crystalline structure of epilayers was investigated by double crystal X-ray diffraction(DCXD). Hall effect on the sample was measured by the van der Pauw method and studied on the carrier density and mobility dependence on temperature. In order to explore the applicability as a photoconductive cell, we measured the sensitivity($\gamma$), the ratio of photocurrent to darkcurrent(pc/dc), maximum allowable power dissipation(MAPD), spectral response and response time. The results indicated that the photoconductive characteristic were the best for the $Cd_{0.53}Zn_{0.47}S$ samples annealed in Cu vapor compare with in Cd, Se, air and vacuum vapour. Then we obtained the sensitivity of 0.99, the value of pc/dc of $1.65{\times}10^7$, the MAPD of 338mW, and the rise and decay time of 9.7ms and 9.3ms, respectively