• Current Photovoltaic Research
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• v.3 no.4
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• pp.116-120
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• 2015

A hybrid transparent conducting layer was applied for Si photodetector. To realize the hybrid transparent conducting layer, a 200 nm-thick ITO layer was deposited onto a Si substrate, following by a solution-processed AgNWs-coating on the ITO. The hybrid transparent conducting layer showed an excellent low electric resistance of $15.9{\Box}/{\Omega}$ with a high optical transparency of 86.89%. Due to these optical and electrical benefits, the hybrid transparent conductor-embedding Si diode provides an extremely high rectifying ratio of 3386. Under light-illumination, the hybrid transparent conductor device provides extremely high photoresponses for broad wavelengths. This implies that a functional design for hybrid transparent conductor is crucial for photoelectric devices and applications.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.444.2-444.2
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• 2014

Transparent conductors (TCs) are typically applied as an ohmic contact layer for photoelectric devices. Recent researches have illuminated a unique rectifying-junction design between a transparent conductor and a semiconductor layer. This approach may lead a significant reduction of device-fabrication steps and cost. A high-performing heterojunction device is presented, which provided significant photoelectric responses. This covers the fabrication processes, rectifying-junction formations and device analyses.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.85-85
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• 2012

For effective light harvesting, a design weighting should be implemented in a front geometry, in which the incident light transmits from a surface into a light-active layer. We designed a three-dimensionally patterned transparent conductor layer for effective light management. A transparent conductive oxide (TCO) film was formed as three-dimensional structures. This efficiently drives the incident light at the front surface into a Si absorber to yield a reduction in reflection and an enhancement of current. This indicates that an optimum architecture for a front TCO surface will provide an effective way for light management in solar cells.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.314.1-314.1
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• 2013

Transparent conducting nanoscale-domes were periodically patterned on a Si substrate by nanoimprint method. Transparent conductor of indium-tin-oxide (ITO) was shaped as a nanodome, which effectively drives the incident light effectively into a light-absorber and therefore induces a substantially enhanced photo-response. An ITO nanodome is electrically isolated from the neighboring nanodomes. This structure benefits to provide a low contact between a Si substrate and a front metal electrode giving an efficient electrical path. The ITO nanodome device showed a significantly enhanced photo-response of 6010 from the value of 72.9 of a planar ITO film. The electrical and optical advantage of an ITO nanodome is suitable for various photoelectric applications.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.458.1-458.1
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• 2014

An effective light-managing structure has been achieved by using a nano-imprint method. A transparent conductor of indium-tin-oxide (ITO) was periodically nanodome-shaped to have a height of 200 nm with a diameter of 340 nm on a p-type Si substrate. This spontaneously formed a heterojunction between the ITO layer and Si substrate and effectively reduced the light-reflection. The ITO nanodome device response was significantly enhanced to 6010 from the value of 72.9 of a planar ITO film. The transparent conducting ITO nanodome structure efficiently manipulates the incident light driving into the light-absorber and can be applied in various photoelectric applications.

• Journal of the Korea Institute of Military Science and Technology
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• v.27 no.1
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• pp.15-23
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• 2024

In order to avoid the high observability due to the cavity resonance or electromagnetic wave leakages from the bridge of a battleship or the cockpit of an aircraft, this paper presents a transparent conductive oxide coated structure to prevent the incoming/outgoing electromagnetic waves. Currently, most of the RCS reduction technologies were focused on radar absorbing material such as paints based on conductive or magnetic materials in the fuselage, and there is not much research on countermeasures for achieving the low observability of materials that required optical transparency in actual weapon systems. In this study, the transmission/reflection and absorption performance of the ITO coated structure according to the change of the surface resistance of the transparent conductor were analyzed. Finally, the relationship between the electromagnetic and optical characteristics was established through fabrication and measurement.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.590-590
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• 2012

A transparent conducting oxide (TCO) layer was applied in crystalline Si (c-Si) solar cells without use of the conventional SiNx-coating. A high quality indium-tin-oxide (ITO) layer was directly deposited on an emitter layer of a Si wafer. Three different types of emitters were formed by controlling the phosphorous diffusion condition. A light-doped emitter forming a thinner emitter junction showed an improved photoconversion efficiency of 14.1% comparing to 13.2% of a heavy-doped emitter. This was induced by lower recombination within a narrower depletion region of the light-doped emitter. In the aspect of light management, the intermediate refractive index of ITO is effective to reduce the light reflection leading the enhanced carrier generation in a Si absorber. For the electrical aspect, the ITO layer serves as an efficient electrical conductor and thus relieves the burden of high contact resistance of the light-doped emitter. Additionally, the ITO works as a buffer layer of Ag and Si and certainly prevents the shunting problem of Ag penetration into Si emitter region. It discusses an efficient design scheme of TCO-embedded emitter Si solar cells.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.87.2-87.2
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• 2015

Transparent conductors are commonly used in photoelectric devices, where the electric energy converts to light energy or vice versa. Energy consumption devices, such as LEDs, Displays, Lighting devices use the electrical energy to generate light by carrier recombination. Meanwhile, solar cell is the only device to generate electric energy from the incident photon. Most photoelectric devices require a transparent electrode to pass the light in or out from a device. Beyond the passive role, transparent conductors can be employed to form Schottky junction or heterojunction to establish a rectifying current flow. Transparent conductor-embedded heterojunction device provides significant advantages of transparent electrode formation, no need for intentional doping process, and enhanced light-reactive surface area. Herein, we present versatile applications of transparent conductors, such as NiO, ZnO, ITO in photoelectric devices of solar cells and photodetectors for high-performing UV or IR detection. Moreover, we also introduce the growth of transparent ITO nanowires by sputtering methods for large scale application.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.243.2-243.2
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• 2015

We report a high-performing nanoscale NiO thin film grown by thermal oxidation of sputtered Ni film. The structural, physical, optical and electrical properties of nanoscale NiO were comprehensively investigated. A quality transparent heterojunction (NiO/ZnO) was formed by large-area applicable sputtering deposition method that has an extremely low saturation current of 0.1 nA. Considerable large rectification ratio of more than 1000 was obtained for transparent heterojunction device. Mott-Schottky analyses were applied to develop the interface of NiO and ZnO by establishing energy diagrams. Nanoscale NiO has the accepter carrier concentration of the order of 1018 cm-3. Nanoscale NiO Schottky junction device properties were comprehensively studied using room temperature impedance spectroscopy.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.363.1-363.1
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• 2016

Transparent and stretchable conductors are expected to be an essential component in future stretchable optoelectronic devices. Until now, two main methods have been commonly employed to fabricate transparent and stretchable conductors by using metal nanomaterials: creating buckling configurations and creating network configurations. In this report, a novel strategy for obtaining transparent and stretchable conductors is presented, one that employs these two main approaches simultaneously. To the best of our knowledge, this proposed configuration of a buckled long nanofiber network in this study has not yet been reported. In order to provide the transparent conductors with dual mode stretchability originating from simultaneous buckled and network configurations, a buckled Au@polyvinylpyrrolidone (PVP) nanofiber network (hereafter referred to BANN for convenience) was fabricated by transferring Au-metallized electrospun PVP nanofibers onto a prestrained polydimethylsiloxane (PDMS) substrate. Our BANN shows considerably lower strain sensitivity of resistance than that of straight Au@PVP nanofiber network. Durability tests conducted by performing cyclic tensile strain reveal that the relative change in resistance of BANN (prestrain = 20%) is quite small after 1000 cycles. We also demonstrate that this BANN exhibits superior performance over widely used indium tin oxide conductors with regard to high optical transmittance and low sheet resistance.