• Korean Journal of Materials Research
• /
• v.27 no.2
• /
• pp.94-99
• /
• 2017

Dinickel-silicide $(Ni_2Si)/glass$ was employed as a counter electrode for a dye-sensitized solar cell (DSSC) device. $Ni_2Si$ was formed by rapid thermal annealing (RTA) at $700^{\circ}C$ for 15 seconds of a 50 nm-Ni/50 nm-Si/glass structure. For comparison, $Ni_2Si$ on quartz was also prepared through conventional electric furnace annealing (CEA) at $800^{\circ}C$ for 30 minutes. XRD, XPS, and EDS line scanning of TEM were used to confirm the formation of $Ni_2Si$. TEM and CV were employed to confirm the microstructure and catalytic activity. Photovoltaic properties were examined using a solar simulator and potentiostat. XRD, XPS, and EDS line scanning results showed that both CEA and RTA successfully led to tne formation of nano $thick-Ni_2Si$ phase. The catalytic activity of $CEA-Ni_2Si$ and $RTA-Ni_2Si$ with respect to Pt were 68 % and 56 %. Energy conversion efficiencies (ECEs) of DSSCs with $CEA-Ni_2Si$ and $RTA-Ni_2Si$catalysts were 3.66 % and 3.16 %, respectively. Our results imply that nano-thick $Ni_2Si$ may be used to replace Pt as a reduction catalytic layer for a DSSCs. Moreover, we show that nano-thick $Ni_2Si$ can be made available on a low-cost glass substrate via the RTA process.

• Bulletin of the Korean Chemical Society
• /
• v.28 no.1
• /
• pp.33-40
• /
• 2007

We have designed and synthesized three Zn(II)-porphyrin derivatives, such as Zn(II) porphyrin ([G-0]Zn-P1) and aryl ether-typed dendron substituted Zn(II)-porphyrin derivatives ([G-1]Zn-P1 and [G-1]Zn-P-CN1). Their chemical structures were characterized by 1H-NMR, FT-IR, UV-vis absorption, EI-mass, and MALDI-TOF mass spectroscopies. Their electrochemical properties were studied by cyclic voltammetry measurement. These Zn(II)-porphyrin derivatives have been used to fabricate dye-sensitized solar cells (DSSCs) based on solid polymeric electrolytes as dye sensitizers and their device performances were evaluated by comparing with that of a standard Ru(II) complex dye. [G-1]Zn-P-CN1 showed the enhanced power conversion efficiency than those of other porphyrin derivatives, as expected. Short-circuit photocurrent density (Jsc), open-circuit voltage (Voc), fill factor (FF), and power conversion efficiency (η) of solid-typed DSSC for [G-1]Zn-P-CN1 were evaluated to be Jsc = 11.67 mA/cm2, Voc = 0.51 V, FF = 0.46, and η = 2.76%, respectively.

• Journal of the Korean Ceramic Society
• /
• v.52 no.2
• /
• pp.114-118
• /
• 2015

$V_2O_5-P_2O_5-ZnO-Sb_2O_3$ glasses modified with BaO and $Al_2O_3$ are synthesized as a sealing material for large-scale dye-sensitized solar cells (DSSCs). A compositional study is performed in order to determine the glass that can be sintered below $500^{\circ}C$ with a high chemical stability against the electrolyte. The flow size of the glasses after the heat treatment and the glass stability are increased with the addition of $Al_2O_3$ and BaO, while the glass transition temperature is decreased. After the reaction with the electrolyte at $60^{\circ}C$ for 72 h, the addition of 5 mol% of BaO and 2 mol% of $Al_2O_3$ considerably enhances the chemical stability of the glass. X-ray diffraction (XRD) and scanning electron microscope (SEM) are used to examine the reaction between the electrolyte and glasses. The structural contribution of the additives is also investigated and discussed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2004.11a
• /
• pp.695-698
• /
• 2004

최근 고유가 시대를 맞으면서 대체 에너지로서 무한자원인 태양빛을 이용하는 염료감응형 태양전지에 대한 관심이 급증하고 있으며, 이미 오래전부터 이에 대한 연구는 이루어져왔다. 한편, 염료감응형 태양전지를 구성하는 여러 분야 중 산화물 전극이나 전해질 또는 염료에 대한 연구는 많은 관심속에 진행되어오고 있는데 반해 상대전극에 대한 연구는 미비한 실정이다. 이에 본 연구에서는, 일반적으로 태양전지의 상대전극으로 사용되어오고 있는 Pt를 스퍼터링법 및 전기도금법을 이용하여 증착한 후 AFM을 통한 표면 형상 및 전기화학적 특성을 바탕으로 비교하여 태양전지의 상대전극으로서 적합한 제조 조건을 결정하였다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2010.06a
• /
• pp.69-69
• /
• 2010

Carbon nano tubes (CNTs) have been attractive candidates for fundamental research studies due to their outstanding physical and chemical properties. High thermal and chemical stability and large surface area make CNTs an ideal platform for many nano materials systems. Several applications such as Several applications were proposed for CNTs many of which are concerned with conductive or high strength composites make them excellent candidates for a variety of energy conversion and storage technologies.

• Electronics and Telecommunications Trends
• /
• v.27 no.1
• /
• pp.38-50
• /
• 2012

박막 태양전지 기술은 현재 가장 큰 시장점유율을 보이고 있는 결정질 Si 태양전지와 비교되는 차세대 태양전지 기술로서 큰 관심을 받고 있다. 결정질 Si 태양전지의 효율보다 높은 효율로서, 훨씬 저가로 생산할 수 있는 수준을 목표로 하여 다양한 종류의 박막 태양전지들이 개발되고 있는데, 본고에서는 그 중에서 가장 많이 연구개발되고 있는 세 종류의 박막 태양전지, 즉, 화합물 반도체 박막 태양전지 중 가장 대표적인 CIGS(Cu(InGa)Se2) 태양전지, 지구상에 가장 풍부한 무기 소재인 Si를 기반으로 하는 비정질 Si 박막 태양전지, 그리고 유기물 기반 태양전지 중 가장 높은 효율을 나타내는 DSSC에 대해서 중점적으로 기술하였다.

• Proceeding of EDISON Challenge
• /
• 2016.03a
• /
• pp.336-338
• /
• 2016

Recent multifunctional two-dimensional material research has triggered huge interests in various modifications for substitution of atoms. Instead of novel metals used as the most popular catalysts, nonprecious transition metals are promising candidates for efficient oxidation-reduction transfers. The recent discovery of $Co@C_2N$ has an alternate possiblity as catalysts for the ORR(Oxygen Reduction Reaction) in DSSc(Dye Sensitized Solar Cell) and OER(Oxygen evolution cobalt oxides). Here we report spin-polarized DFT calculations of the structure doped Iron that is one of ferromagnetism atoms like Co to provide a basic desciption of the ferromagnetism of the elemental metals. The spin-density-funtional results present the most stable state energetically is when having pairwise up/down spin.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2010.02a
• /
• pp.316-316
• /
• 2010

Six metal-free organic dyes having thiophene (1), benzene-thiophene (2), thiophene-benzene (3), thiophene-pyridine(4), thiophene-thiophene (5), and pyridine (6) linkers between 9,9-dimethylfluorenyl terminal group and $\alpha$-cyanoacrylic acid anchor were synthesized. Among them, organic dye 5 showed the longest ${\lambda}}max$ value (424 nm) in UV-Vis absorption spectrum, better incident monochromatic photon-to-current conversion efficiency (IPCE), highest short circuit photocurrent density (JSC, 9.33 mA2/cm2), and highest overall conversion efficiency ($\eta$, 3.91%).

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2008.05a
• /
• pp.45.1-45.1
• /
• 2008

• Bulletin of the Korean Chemical Society
• /
• v.32 no.8
• /
• pp.2671-2676
• /
• 2011

Nanocrystalline $TiO_2$ spherical particle (NP) with a dimension of 5 ${\times}$ 5.5 nm and several nanorods (NR) with different aspect ratios (diameter ${\times}$ length: 5 ${\times}$ 8.5, 4 ${\times}$ 15, 4 ${\times}$ 18 and 3.5 ${\times}$ 22 nm) were selectively synthesized by a solvothermal process combined with non-hydrolytic sol-gel reaction. With varying the molar ratio of TTIP to oleic acid from 1:1 to 1:16, the NRs in the pure anatase phase were elongated to the c-axis direction. The prepared NP and NRs were applied for the formation of nanoporous $TiO_2$ layers in dye-sensitized solar cell (DSSC). Among them, NR2 ($TiO_2$ nanorod with 4 ${\times}$ 15 nm) exhibited the highest cell performance: Its photovoltaic conversion efficiency (${\eta}$) of 6.07%, with $J_{sc}$ of 13.473 mA/$cm^2$, $V_{oc}$ of 0.640 V, and FF of 70.32%, was 1.44 times that of NP with a size of 5 ${\times}$ 5.5 nm. It was observed from the transient photoelectron spectroscopy and the incident photon to current conversion efficiency (IPCE) spectra that the $TiO_2$ films derived from NR2 demonstrate the longest electron diffusion length ($L_e$) and the highest external quantum efficiency (EQE).