• 한국전기전자재료학회논문지
• /
• 제30권11호
• /
• pp.734-739
• /
• 2017

We prepared $SnS_x$ thin films on both soda-lime glass (SLG) and molybdenum(Mo)/SLG substrates by a two-step process using a Sn precursor followed by sulfur reaction in rapid thermal annealing (RTA) at different sulfurization temperatures ($Ts=200^{\circ}C$, $230^{\circ}C$, $250^{\circ}C$, and $300^{\circ}C$) and annealing times ($t_s=10min$ and 30 min). The single SnS phase was dominant for $200^{\circ}C{\leq}T_s$<$250^{\circ}C$, while an additional phase of $SnS_2$ was appeared at $T_s{\geq}250^{\circ}C$ alongside SnS. The SnS grains in all the samples showed strong growth along the preferred [040] direction. The band-gap energy ($E_g$) of the films was estimated to be 1.24 eV.

• 한국전기전자재료학회논문지
• /
• 제29권2호
• /
• pp.95-100
• /
• 2016

We fabricated a tin sulfide (SnS) layer with Sn/Mo/glass layers followed by a RTP (rapid thermal processing), and studied the film growth and structural characteristics as a function of annealing temperature and time. The elemental sulfur (S) was cracked thermally and applied to form SnS polycrystalline film out of the Sn percursor at pre-determined pressures in the RTP tube. The sulfurization was done at the temperature from $200^{\circ}C$ to $500^{\circ}C$ for a time period of 10 to 40 min. At ${\leq}300^{\circ}C$, 20 min., p-type SnS thin films was grown and showed the best composition of at.% of [S]/[Sn] $${\sim_=}$$ 1 and [111] preferred orientation as investigated from using XRD (X-ray diffraction) analysis and EDS (energy dispersive spectroscopy) and SEM (scanning electron microscopy), and optical absorption by a UV-VIS spectrometer. In this paper, we report the details of growth characteristics of single phase SnS thin film as a function of annealing temperature and time associated with the pressure and ambient gas in the RTP tube.

• Transactions on Electrical and Electronic Materials
• /
• 제10권4호
• /
• pp.135-139
• /
• 2009

$H_2S$ micro-gas sensors have been developed employing $SnO_2$:CuO composite thin films. The films were prepared by e-beam evaporation of Sn and Cu metals on silicon substrates, followed by oxidation at high temperatures. Results of various studies, such as scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) reveal that $SnO_2$ and CuO are mutually non-reactive. The CuO grains, which in turn reside in the inter-granular regions of $SnO_2$, inhibit grain growth of $SnO_2$ as well as forming a network of p-n junctions. The film showed more than a 90% relative resistance change when exposed to $H_2S$ gas at 1 ppm in air at an operating temperature of $350^{\circ}C$ and had a short response time of 8 sec.

• 한국결정성장학회지
• /
• 제13권5호
• /
• pp.254-259
• /
• 2003

Sol-gel dip coating법으로 soda lime glass 기판 위에 ATO(antimony-doped tin oxide) 투명전도막을 제조할 때, 기판 위에 형성된 $SiO_2$ barrier 층 및 $N_2$ gas annealing 에 따른 광투과율 및 전기적 특성에 대한 효과를 정량적으로 측정하고, XPS(X-ray photoelectron spectroscopy) 분석을 통해 고찰하였다. $SiO_2$ barrier층을 갖는 glass 기판 위에 코팅된400 nm 두께의 ATO 박막을 질소분위기에서 annealing한 결과, 광 투과율은 84%그리고 전기저항은 약 $5.0\times 10^{-3}\Omega \textrm{cm}$로 측정되었다 XPS 분석결과 이러한 우수한 전기전도성은 $SiO_2$ buffer층이 glass 기판으로부터 Na 이온의 확산을 막아 ATO막 내에 $Na_2SnO_3$ 및 SnO와 같은 2차상 불순물의 형성을 억제하여 막 내부의 Sb의 농도 및 $Sb^{5+}/Sb^{3+}$ 비를 증가시키고, $N_2$ annealing은 $Sb^{5+}$ 도 환원시키지만 $Sn^{4+}$를 환원시키는 효과가 크게 작용하였기 때문으로 사료된다.

• 한국초전도ㆍ저온공학회논문지
• /
• 제18권4호
• /
• pp.1-4
• /
• 2016

We investigated the relation between the Cu-O bond length and the superconducting properties of $BaSnO_3$ (BSO)-added $GdBa_2Cu_3O_{7-x}$ (GdBCO) thin films by using extended x-ray absorption fine structure (EXAFS) spectroscopy. 4 wt.% $BaSnO_3$ (BSO) added $GdBa_2Cu_3O_{7-x}$ (GdBCO) thin films with varying thickness from $0.2{\mu}m$ to $1.0{\mu}m$ were fabricated by using pulsed laser deposition (PLD) method. The transition temperature ($T_c$) and the residual resistance ratio (RRR) of the GdBCO films increased with increasing thickness up to $0.8{\mu}m$, where the crystalline BSO has the highest peak intensity, and then decreased. This uncommon behaviors of $T_c$ and RRR are likely to be created by the addition of BSO, which may change the ordering of GdBCO atomic bonds. Analysis from the Cu K-edge EXAFS spectroscopy showed an interesting thickness dependence of ordering behavior of BSO-added GdBCO films. It is noticeable that the ordering of Cu-O bond and the transition temperature are found to show opposite behaviors in the thickness dependence. Based on these results, the growth of BSO seemingly have evident effect on the alteration of the local structure of GdBCO film.