• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.1
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• pp.37-43
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• 2012

We were studied that AZO conductive thin film can substitute for FTO electrode in dye sensitized solar cell. Three types of AZO films were deposited on soda-lime glass(AZO/glass, AZO/AZO/glass, textured AZO/AZO/glass) using RF magnetron sputtering process and investigated their properties of electrical, optical, and photoelectric conversion rate. The textured AZO/AZO/glass has the lowest resistivity of $3.079{\times}10^{-4}\;{\Omega}cm$ among other films. And the optical transmittance rate was better than both non textured AZO/AZO/glass and FTO/glass in the visible region. After manufacturing dye solar cells using the three types of AZO films, the textured AZO/AZO/glass showed the highest photoelectric conversion rate of 3.68% among AZO samples. But the transformation rate was slightly lower than FTO cells (4.52%). However, the conductive film of textured AZO/AZO/glass can be applicable to use an electrode in solar cells as cost-effective products.

• Journal of information and communication convergence engineering
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• v.9 no.4
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• pp.461-465
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• 2011

An aluminum doped zinc oxide (AZO) film for front contacts of thin film solar cells, in this work, were deposited by r.f. magnetron sputtering, and then etched in diluted hydrochloric acid solution for different times. Effects of surface texturing on the electro-optical properties of AZO films were investigated. Also, to clarify the light trapping of textured AZO film, amorphous silicon thin film solar cells were fabricated on the textured AZO/glass substrate and the performance of solar cells were studied. After texturing, the spectral haze at the visible range of 400 ~750 nm increased substantially with the etching time, without a change in the resistivity. The conversion efficiency of amorphous Si solar cells with textured AZO film as a front electrode was improved by the increase of short-circuit current density ($J_{sc}$), compared to cell with flat AZO films.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.594-594
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• 2012

Al doped ZnO (AZO) thin films were deposited on textured glass substrate by magnetron sputtering method. Also, AZO films on textured glass were etched by hydrochloric acid (HCl). Average thickness of etched AZO films are 90 nm. We observed morphology of AZO film by AFM with various etchant concentration and etching time. Etched AZO films have low resistivity and high haze. The surface RMS roughness of AZO film was increased from 53.8 nm to 84.5 nm. The haze ratio was also enhanced in above 700 nm of wavelength due to light trapping effect was increased by rough AZO surface. The etched AZO films on textured glass are applicable to fabricate solar cell.

• 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.

• Transactions on Electrical and Electronic Materials
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• v.17 no.2
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• pp.98-103
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• 2016

The surface morphology of the front transparent conductive oxide (TCO) films plays a vital role in amorphous silicon thin film solar cells (a-Si TFSCs) due to their high transparency, conductivity and excellent light scattering properties. Recently, plasma textured glass surface morphologies received much attention for light trapping in a-Si TFSCs. We report various plasma textured glass surface morphologies for the high efficiency of a-Si TFSCs. Plasma textured glass surface morphologies showed high rms roughness, haze ratio with micro- and nano size surface features and are proposed for future high efficiency of a-Si TFSCs.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.391-394
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• 2002

Transparent conductive oxides (TCO) are necessary as front electrode for most thin film solar cell. In our paper, transparent conducting aluminum-doped Zinc oxide films (ZnO:Al) were prepared by rf magnetron sputtering on glass (Corning 1737) substrate as a variation of the deposition condition. After deposition, the smooth ZnO:Al films were etched in diluted HCl (0.5%) to examine the electrical and surface morphology Properties as a variation of the time. The most important deposition condition of surface-textured ZnO films by chemical etching is the processing pressure and the substrate temperature. In low pressures (0.9 mTorr) and high substrate temperatures ($\leq$30$0^{\circ}C$), the surface morphology of films exhibits a more dense and compact film structure with effective light-trapping to apply the silicon thin film solar cells.

• Proceedings of the Materials Research Society of Korea Conference
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• 2010.05a
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• pp.4.1-4.1
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• 2010

In the first part, after discussing works on nacre, a soft-hard composite found in nature, including a simulation on network mimicking nacre [1-4], we talk on a simple model of spider webs, another example of natural soft-hard structure [5]. We demonstrate that the web network is free of stress concentrations because the radial threads are stronger than the spiral threads. In the second part, after reviewing our works on wetting on textured surfaces [6-8], we discuss penetration into textured surface and instability of a liquid film on textured substrates during spin coating [9,10].

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.7
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• pp.446-449
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• 2015

An improvement of light-extraction efficiency of organic light-emitting diodes was studied by using random-textured films (RTF). Device was made in a structure of RTF/glass/ITO/TPD/$Alq_3$/LiF/Al. RTF mold was made by spreading PDMS solution on a sandpaper. By pressing this mold on the glass substrate pre-coated with ZPU material, the RTF was obtained. From this study, there was an improvement of external quantum efficiency by about 30% in the device with the random-textured film (RTF 40) compared to that of the reference one.

• Current Photovoltaic Research
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• v.2 no.3
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• pp.95-102
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• 2014

Light trapping techniques can change the propagation direction of incident light and keep the light longer in the absorption layers of solar cells to enhance the power conversion efficiency. In thin film silicon (Si) solar cells, the thickness of absorption layer is generally not enough to absorb entire available photons because of short carrier life time, and light induced degradation effect, which can be compensated by the light trapping techniques. These techniques have been adopted as textured transparent conduction oxide (TCO) layers randomly or periodically textured, intermediate reflection layers of tandem and triple junction, and glass substrates etched by various patterning methods. We reviewed the light trapping techniques for thin film Si solar cells and mainly focused on the commercially available techniques applicable to textured TCO on patterned glass substrates. We described the characterization methods representing the light trapping effects, texturing of TCO and showed the results of multi-scale textured TCO on etched glass substrates. These methods can be used tandem and triple thin film Si solar cells to enhance photo-current and power conversion efficiency of long term stability.

• Transactions on Electrical and Electronic Materials
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• v.17 no.5
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• pp.275-279
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• 2016

This is a brief review on light trapping in Si based thin film solar cells with textured surfaces and transparent conducting oxide front electrodes. The light trapping scheme appears to be essential in improving device efficiency over 10%. As light absorption in a thin film solar cells is not sufficient, light trapping becomes necessary to be effectively implemented with a textured surface. Surface texturing helps in the light trapping, and thereby raises short circuit current density and its efficiency. Such a scheme can be adapted to single junction as well as tandem solar cell, amorphous or micro-crystalline devices. A tandem cell is expected to have superior performance in comparison to a single junction cell and random surface textures appears to be preferable to a periodic structures.