• Proceedings of the Korean Vacuum Society Conference
• /
• 2013.02a
• /
• pp.688-688
• /
• 2013

Al-doped ZnO (AZO) thin films have attracted a lot of attention as a cheap transparent conducting oxide (TCO) material that can replace the expensive Sn-doped In2O3. In particular, AZO thin films are widely used as a window layer of chalcogenide-based thin film solar cells such as Cu(In,Ga)Se2 and Cu2ZnSnS4 (CZTS). Mostly important requirements for the window layer material of the thin film solar cells are the high transparency and the low sheet resistance, because they influence the light absorption by the activelayer and the electron collection from the active layer, respectively. In this study, we prepared the AZO thin films by RF magnetron sputtering using a ZnO/Al2O3 (98：2wt%) ceramic target, and the effect of the sputtering condition such as the working pressure, RF power, and the working distance on the optical, electrical, and crystallographic properties of the AZO thin films was investigated. The AZO thin films with optimized properties were used as a window layer of CZTS thin film solar cells. The CZTS active layers were prepared by the electrochemical deposition and the subsequent sulfurization process, which is also one of the cost-effective synthetic approaches. In addition, the solar cell properties of the CZTS thin film solar cells, such as the photocurrent density-voltage (J-V) characteristics and the external quantum efficiency (EQE) were investigated.

• Journal of the Semiconductor & Display Technology
• /
• v.19 no.1
• /
• pp.93-96
• /
• 2020

Polyimide thin film was prepared by annealing the polyamic acid that was synthesized through co-deposition of diamine and dianhydride. The polyamic acid and polyimide thin film were characterized with FT-IR and HR FE-SEM. The average roughness of the film surface, evaluated with AFM, were 0.385 nm and 0.299 nm after co-deposition, and annealing at 120 ℃ respectively. OLED was passivated with the polyimide layer of 200 nm thickness. While the inorganic passivation layer enhances the WVTR of OLED, the organic passivation layer gives flexibility to the OLED. The in-situ passivation of OLED with organic thin film layer provides the leading technique to develop flexible OLED Display.

• Proceedings of the Korean Ceranic Society Conference
• /
• 2000.04a
• /
• pp.121-121
• /
• 2000

• Proceedings of the KIEE Conference
• /
• 2000.07c
• /
• pp.1779-1781
• /
• 2000

Pd doped $SnO_2$ thin film sensors were prepared on alumina substrate by rf magnetron sputtering method. The sensitivity of thin film was investigated by varying the heat-treatment temperature, film thickness and gas species. The thin film heat-treated at 600$^{\circ}C$ and film thickness of 5000${\AA}$ showed the highest sensitivity at an operating temperature of 400$^{\circ}C$.

• Korean Chemical Engineering Research
• /
• v.48 no.2
• /
• pp.218-223
• /
• 2010

The zinc oxide thin film, which can be applied as the gas sensor of a semiconductor type, was grown on the silicon substrate by CFR(continuous flow reaction) method in this study. The growth property and the electrical property of the zinc oxide thin films synthesized by CFR method were also investigated. Zinc acetate solutions of 0.005~0.02 M were used as the precursor for the preparation of zinc oxide thin films. The size of ZnO particles consisted on the zinc oxide thin film increased not only with increasing concentration of precursor, but also the thickness of thin film increased. The growth rate of zinc oxide thin film by CFR method was proportionably depend on the concentration of precursor and the uniform ZnO thin film was prepared when zinc acetate of 0.01 M is used as the precursor. The charged currents on the zinc oxide thin films were obtained as its electrical property by I-V meter, and increased agree with increasing the thickness of zinc oxide thin film. Thus, it was concluded that the charged current on the zinc oxide thin film can be controlled with changing concentration of precursor solution in CFR method. The charged currents on the zinc oxide thin films also decreased when ZnO thin film is exposed under hydrogen sulfide of 500 ppmv at $300^{\circ}C$ for 5 min. From these results, it could be confirmed that the zinc oxide thin film prepared by CFR method can be used for the detection of sulfur compounds.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2014.02a
• /
• pp.442-442
• /
• 2014

Although electrochemical capacitors (ECs), also known as supercapacitors or ultracapacitors, is one of the most promising energy-storage devices because of its high power density, super-high cycle life, and safe operation. We herein report a synthesis of graphene-based flexible films by kneading method. Thus, a device can be readily made by sandwiching a polymer membrane included ionic liquid electrolytes between two identical graphene-based flexible films. Devices made with these electrodes exhibit ultrahigh energy density values while maintaining the high power density and excellent cycle stability of ECs. Moreover, these ECs maintain excellent electrochemical attributes under high mechanical stress and thus hold promise for high-energy, flexible electronics.

• Journal of the Korean Ceramic Society
• /
• v.52 no.5
• /
• pp.304-307
• /
• 2015

To reduce the lateral conduction loss of thin-film-processed cathodes, the microstructure of the thin-film cathode is engineered to contain a denser bridging layer in the middle. By doing so, the characteristic crack-like pores that separate the cathode domains in thin-film-processed cathodes and hamper lateral conduction are better connected and, as a result, the sheet resistance of the cathode is effectively reduced by a factor of 5. This induces suppression of the lateral conduction loss and expansion of the effective current collecting area; the cell performance is improved by more than 30%.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.30 no.4
• /
• pp.199-203
• /
• 2017

$ZrO_2/PSS$ thin film with a high refractive index was fabricated on a glass substrate by a layer-by-layer self-assembly method. The surface morphology and thickness of the fabricated $ZrO_2/PSS$ thin films were measured as a function of the number of $(ZrO_2/PSS)n$. As the number of $(ZrO_2/PSS)n$ increased from n = 5 to n = 20, RMS roughness decreased from 29.01 nm to 8.368 nm. The $ZrO_2$ thin films exhibited high transmittance of 85% or more; and the 15-bilayer thin film exhibited the highest transmittance among the samples. The transmittance of the fabricated $(ZrO_2/PSS)_{15}$ thin film was ca. 90.8% in the visible range. The refractive index of the glass substrate coated by a $(ZrO_2/PSS)_{15}$ thin film with a thickness of 160 nm increased from ca. 1.52 to 1.74 at the 632 nm wavelength.

• Transactions on Electrical and Electronic Materials
• /
• v.18 no.2
• /
• pp.93-96
• /
• 2017

The structural, electrical and optical properties of Ti thin films fabricated by dual magnetron sputtering were investigated under various film thicknesses. The fabricated Ti thin films exhibited uniform surfaces, crystallinity, various grain sizes, and with various film thicknesses. Also, the crystallinity and grain size of the Ti thin films increased with the increase of film thickness. The electrical properties of Ti thin films improved with the increase of film thickness. The results showed that the performance of TCO-less DSSC critically depended on the film thickness of the Ti working electrodes, due to the conductivity of Ti thin film. However, the maximum conversion efficiency of TCO-less DSSC was exhibited at the condition of 100 nm thickness due to the surface scattering of photons caused by the variation of grain size.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1995.11a
• /
• pp.277-280
• /
• 1995

We had experiment using LB method that can fabricate molecular order ultra-thin film below 100${\AA}$. LB mettled has known as main technology of information society in 21C, because it is nut only free oriention and alignment of molecular but also ability of thickness control as molecular order. In this paper, the fabricated condition and physical properities of functional ultra-thin film of molecular order was investigated and highly efficient ultra-thin film capacitor was fabricated by using ultra-thin LB film for application as electronic device. Possibility of ultra-thin film capacitor was researched by analizing rind measuring electrical properties. Polyimide ultra-thin LB film capacitor was fabricated, ensured theoretically rind experimentally its possibility in range of 10Hz∼ 1MHz through its frequency characteristics.