• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.107-107
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• 2011

오늘 날 transparent conductive oxide는 다양한 분야에서 활용되고 있다. 최근에는 태양전지 분야에서도 많이 활용되고 있으며, 초기에는 transmittance 및 낮은 sheet resistance 특성을 가지는 ITO가 많이 활용되었지만 thin film solar cell와 같이 hydrogenation 공정에 약한 ITO보다는 Al-doped ZnO가 사용되기 시작하면서 많은 연구가 진행되고 있다. 본 연구에서는 thin film solar cell 및 silicon heterojunction solar cell에 적용 가능한 Al-doped ZnO에 관한 연구로써 a-Si:H의 Si-H bonds에 영향을 주지 않는 낮은 영역의 substrate temperature와 power로 Al-doped ZnO를 형성하고 상기 parameter에 따른 Al-doped ZnO의 특성 변화에 대해서 분석하였다. 특히 substrate temperature가 변화할수록 carrier concentration 및 sheet resistance가 많은 변화를 보였으며 이로 인하여 transmittance 특성이 온도에 따라 좋아지다가 너무 높은 온도에서는 오히려 좋지 않게 되었다. 이는 너무 높은 carrier concentration은 free carrier absorption에 의해 transmittance 특성을 오히려 좋지 않게 한다. 우리는 본 연구를 통해 92.677% (450 nm), 90.309% (545 nm), 94.333% (800 nm)의 transmittance를 얻을 수 있었다.

• 한국재료학회지
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• 제30권3호
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• pp.131-135
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• 2020

Silver nanowire (AgNW) networks have been adopted as a front electrode in Cu(In,Ga)Se2 (CIGS) thin film solar cells due to their low cost and compatibility with the solution process. When an AgNW network is applied to a CIGS thin film solar cell, reflection loss can increase because the CdS layer, with a relatively high refractive index (n ~ 2.5 at 550 nm), is exposed to air. To resolve the issue, we apply solution-processed ZnO nanorods to the AgNW network as an anti-reflective coating. To obtain high performance of the optical and electrical properties of the ZnO nanorod and AgNW network composite, we optimize the process parameters - the spin coating of AgNWs and the concentration of zinc nitrate and hexamethylene tetramine (HMT - to fabricate ZnO nanorods. We verify that 10 mM of zinc nitrate and HMT show the lowest reflectance and 10% cell efficiency increase when applied to CIGS thin film solar cells.

• Journal of Electrical Engineering and Technology
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• 제5권1호
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• pp.146-150
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• 2010

A new type of dye-sensitized solar cell (DSC) based on a porous type Ti electrode without using a transparent conductive oxide (TCO) layer is fabricated for low-cost high-efficient solar cell application. The TCO-free DSC is composed of a glass substrate/dye-sensitized $TiO_2$ nanoparticle/porous Ti layer/electrolyte/Pt sputtered counter electrode. The porous Ti electrode (~350 nm thickness) with high conductivity can collect electrons from the $TiO_2$ layer and allows the ionic diffusion of $I^-/I_3{^-}$ through the hole. The vacuum annealing treatment is important with respect to the interfacial necking between the metal Ti and porous $TiO_2$ layer. The efficiency of the prepared TCO-free DSC sample is about 3.5% (ff: 0.48, $V_{oc}$: 0.64V, $J_{sc}$: 11.14 mA/$cm^2$).

• Current Applied Physics
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• 제18권12호
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• pp.1583-1591
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• 2018

We analysed perovskite $CH_3NH_3PbI_{3-x}Cl_x$ inverted planer structure solar cell with nickel oxide (NiO) and spiroMeOTAD as hole conductors. This structure is free from electron transport layer. The thickness is optimized for NiO and spiro-MeOTAD hole conducting materials and the devices do not exhibit any significant variation for both hole transport materials. The back metal contact work function is varied for NiO hole conductor and observed that Ni and Co metals may be suitable back contacts for efficient carrier dynamics. The solar photovoltaic response showed a linear decrease in efficiency with increasing temperature. The electron affinity and band gap of transparent conducting oxide and NiO layers are varied to understand their impact on conduction and valence band offsets. A range of suitable band gap and electron affinity values are found essential for efficient device performance.

• 한국세라믹학회지
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• 제50권5호
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• pp.309-318
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• 2013

Graphene has attracted considerable attention since its first production from graphite in 2004, due to its outstanding physical and chemical properties. The development of production methodsfor large scale, high quality graphene films is an essentialstep toward realizing graphene applications such as transparent, conductive film. Chemical deposition methods, using metal catalystsand gaseous carbon sources, have been extensively developed for large area synthesis. In this paper, wereview recent progress ingraphene production, and survey the role of graphene electrodes in various electronic devices such as touch panels, solar cells, solid statelighting and microelectronic devices.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1351_1352
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• 2009

We deposited $SnO_2$:F thin films by atomospheric pressure chemical vapor deposition(APCVD) on corning glass. $SnO_2$:F films were used as transparent conductive oxide (TCO) electrode for Si thin film solar cells. We have investigated structural, electrical and optical properties of $SnO_2$:F thin films and fabricated thin film Si solar cells by plasma enhanced CVD(PECVD) on $SnO_2$:F thin films The cells were characterized by I-V measurement using AM1.5 spectra. Conversion efficiency of our cells were between 5.61% and 6.45%.

• 한국태양에너지학회 논문집
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• 제39권4호
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• pp.25-39
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• 2019

Luminescent solar concentrator (LSC), consisting of luminophore included glass or substrate with edge-mounted photovoltaic cell, is semi-transparent, energy harvesting devices. The luminophore absorbs incident solar light and re-emit photons, while the waveguide plate allows re-emitted photons to reach edge or bottom mounted photovoltaic cells with reduced losses. If the area of LSC is much larger than that of photovoltaic cell, this system can effectively concentrate solar light. In order to improve the performance of LSC, new materials and optical structures have been suggested by many research groups. For decreasing re-abosprion losses, it is essential to minimize the overlap between absorption and photoluminescence solar spectrum of luminophoroe. Moreover, the combination of selective top reflector and reflective optical cavity structure significantly boosts the waveguide efficiency in the LSC. As a result of many efforts, commercially available LSCs have been demonstrated and verified in the outdoor. Also, it is expected to generate electricity in buildings by replacing conventional glass to LSCs.

• 대한기계학회논문집B
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• 제37권6호
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• pp.577-582
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• 2013

AZO(Aluminium-doped Zinc Oxide)는 기존의 LCD, OLED, 광센서, 유기태양전지 등의 투명전극에 널리 사용되는 ITO(Indium Tin Oxide)를 대체하기 위한 물질로 주목받고 있다. 본 연구에서는 유기태양전지의 투명 전극으로 많이 사용되는 ITO 를 대체하기 위해 원자층 증착(ALD) 공정의 저온 선택적 증착 특성을 이용하여 유연성 폴리머인 PEN 기판상에 AZO 투명전극을 직접 패턴방식으로 제조하고, 그 투명전극의 구조적, 전기적, 광학적 특성을 평가하였다. 전기적, 광학적 특성 결과들로부터 원자층 증작공정의 저온 선택적 증착 특성을 통해 형성된 AZO 투명전극의 유기태양전지로의 적용 가능성을 확인할 수 있었다.

• 정보저장시스템학회논문집
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• 제9권2호
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• pp.42-47
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• 2013

In this study, we have experimentally analyzed how the surface properties of transparent electrode layer influence the photovoltaic performance of bulk heterojunction organic solar cell by the contact angle measurement and X-ray photoelectron spectroscopy(XPS) observation. As a result, the power conversion efficiency of test devices improved from 0.64% to 1.83% and 2.15% by UV-ozone exposure and $O_2$ plasma treatment, respectively. Thus, we conclude that the surface activation process is very important for better performance and stability in addition to the cleaning process of carbonate residue on the surface.

• Current Photovoltaic Research
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• 제2권3호
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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.