• Journal of IKEEE
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• v.25 no.1
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• pp.69-75
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• 2021

In this work, we consider the fabrication method and electrical characteristics of dye-sensitized solar cells (DSSCs), which use titanium (Ti) metal thin films to replace expensive fluorine tin oxide (FTO) electrodes. The thickness of the Ti thin film was changed by adjusting the deposition time of the Ti, and the surface resistance decreased as the thickness of the Ti thin film became thicker. The thickness of the Ti thin film was shown to be similar to the surface resistance of the FTO thin film at approximately 190nm and the DSSC with a thickness of approximately 250nm showed the highest energy conversion efficiency of 4.24%. Furthermore, the possibility of commercialization was confirmed by fabricating and evaluating the DSSC module.

• Bulletin of the Korean Chemical Society
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• v.24 no.7
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• pp.953-956
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• 2003

Hexagonal GaN (h-GaN) films have been grown on Si(111) substrates by metal organic chemical vapor deposition using the azidodiethylgallium methylamine adduct, Et₂Ga(N₃)·NH₂Me, as a new single precursor. Deposition was carried out in the substrate temperature range 385-650 °C. The GaN films obtained were stoichiometric and did not contain any appreciable amounts of carbon impurities. It was also found that the GaN films deposited on Si(111) had the [0001] preferred orientation. The photoluminescence spectrum of a GaN film showed a band edge emission peak characteristic of h-GaN at 378 nm.

• Korean Journal of Materials Research
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• v.29 no.11
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• pp.715-719
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• 2019

Molybdenum is a low-resistivity transition metal that can be applied to silicon devices using Si-metal electrode structures and thin film solar cell electrodes. We investigate the deposition of metal Mo thin film by plasma-enhanced atomic layer deposition (PE-ALD). $Mo(CO)_6$ and $H_2$ plasma are used as precursor. $H_2$ plasma is induced between ALD cycles for reduction of $Mo(CO)_6$ and Mo film is deposited on Si substrate at $300^{\circ}C$. Through variation of PE-ALD conditions such as precursor pulse time, plasma pulse time and plasma power, we find that these conditions result in low resistivity. The resistivity is affected by Mo pulse time. We can find the reason through analyzing XPS data according to Mo pulse time. The thickness uniformity is affected by plasma power. The lowest resistivity is $176{\mu}{\Omega}{\cdot}cm$ at $Mo(CO)_6$ pulse time 3s. The thickness uniformity of metal Mo thin film deposited by PE-ALD shows a value of less than 3% below the plasma power of 200 W.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.1
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• pp.26-29
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• 2006

Transparent ZnO thin films were prepared by KrF pulsed laser deposition (PLD) technique and applied to a bottom-gate type thin film transistor device as an active channel layer. A high conductive crystalline Si substrate was used as an metal-like bottom gate and SiN insulating layer was then deposited by LPCVD(low pressure chemical vapour deposition). An aluminum layer was then vacuum evaporated and patterned to form a source/drain metal contact. Oxygen partial pressure and substrate temperature were varied during the ZnO PLD deposition process and their influence on the thin film properties were investigated by X-ray diffraction(XRD) and Hall-van der Pauw method. Optical transparency of the ZnO thin film was analyzed by UV-visible phometer. The resulting ZnO-TFT devices showed an on-off ration of $10^6$ and field effect mobility of 2.4-6.1 $cm^2/V{\cdot}s$.

• Journal of the Korean Ceramic Society
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• v.37 no.11
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• pp.1126-1129
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• 2000

The crystallographic orientations of $Ba_{0.6}$S $r_{0.4}$Ti $O_3$(BST) thin film deposited by a metal-organic chemical vapor deposition on (111) textured Pt electrode were studied with a transmission electron microscopy. The fully crystallized BST thin film (50nm) has (100) and (110) preferred orientations. A high resolution transmission electron microscopy study has revealed the crystallographic orientation relationships between BST thin film and Pt electrode. These relationships explained the preferred orientation of BST film on (111) textured Pt electrode. With these results, we could represent the atomic arrangement at the BST/Pt interface.e.e.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1993.05a
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• pp.96-99
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• 1993

Electrical properties of the Thin Film Transistor(TFT) electrode metal films were investigated through the Test Elements Group(TEG) experiment. The main purpose of this investigation was to characterize the electrical resistance properties of patterned metal films with respect to the variations of film thickness and TEG metal line width. Aluminum(Al), Tantalum(Ta) and Chromium(Cr) that are currently used as TFT electrode films were selected as the probed metal films. To date, no work in the electrical characterizations of patterned electrodes of a-Si TFT was accomplished. Bulk resistance$(R_b)$, sheet resistance$(R_s)$, and resistivities($\rho$) of TEG patterned metal lines were obtained. Electrical continuity test of metal film lines was also performed in order to investigate the stability of metallization process. Almost uniform-linear variations of the electrical properties with respect to the metal line displacements was also observed.

• Korean Journal of Metals and Materials
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• v.48 no.2
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• pp.163-168
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• 2010

We here describe the laser-direct patterning of nanostructured metal thin films. This method involves light-matter interaction in which a pulsed laser beam impinging on the film generates a thermoelastic force that plays a role to detach the film from the substrate or underlying layers. A moderate cohesion of the nanostructured film enables localized desorption of the material upon irradiation by a spatiallymodulated laser beam, giving good fidelity with the transfered pattern. This photoresist-free process provides a simple high-resolution scheme for patterning metal thin films.

• Journal of the Korean Ceramic Society
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• v.45 no.12
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• pp.796-801
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• 2008

$LaGaO_3$ thin film was prepared on Ni-Fe metal porous substrate by Pulsed Laser Deposition method. By the thermal reduction, the dense $NiO-{Fe_3}{O_4}$ substrate is changed to a porous Ni-Fe metal substrate. The volumetric shrinkage and porosity of the substrate are controlled by the reduction temperature. It was found that a thermal expansion property of the Ni-Fe porous metal substrate is almost the same with that of $LaGaO_3$ based oxide. $LaGaO_3$ based electrolyte films are prepared by the pulsed laser deposition (PLD) method. The film composition is sensitively affected by the deposition temperature. The obtained film is amorphous state after deposition. After post annealing at 1073K in air, the single phase of $LaGaO_3$ perovskite was obtained. Since the thermal expansion coefficient of the film is almost the same with that of LSGM film, the obtained metal support LSGM film cell shows the high tolerance against a thermal shock and after 6 min startup from room temperature, the cell shows the almost theoretical open circuit potential.

• Proceedings of the Korean Vacuum Society Conference
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• 1998.06a
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• pp.93-93
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• 1998

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.3
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• pp.154-159
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• 2015

In this paper, we propose a numerical method to model temperature dependent threshold voltage shift observed in metal oxide thin-film transistors (TFTs). The proposed model is then implemented in AIM-SPICE circuit simulation tool. The proposed method consists of modeling the well-known stretched-exponential time dependent threshold voltage shift and their temperature dependent coefficients. The outputs from AIM-SPICE tool and the stretched-exponential model at different temperatures in the literature are compared and they show a good agreement. Since metal oxide TFTs are the promising candidate for flat panel displays, the proposed method will be a good stepping stone to help enhance reliability of fast-evolving display circuits.