• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.313.1-313.1
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• 2013

현재 결정질 실리콘 태양전지의 전 후면 전극의 형성은 스크린 프린팅 방법이 주를 이루고 있다. 스크린 프린팅 방법은 쉽고 빠르게 인쇄가 가능한 반면 단가가 높고 금속 페이스트에 첨가된 여러 혼합물에 의해서 전극과 기판 사이의 저항이 크다는 단점이 있다. 본 논문에서는 스크린 프린팅 방법으로 태양전지의 seed layer를 인쇄하고, Cu도금을 진행함으로써 태양전지의 전기적 특성을 비교하였다. 주요 전극 형성을 Cu 도금을 사용함으로써 전극과 기판사이의 저항을 감소시키고 값비싼 Ag페이스트를 값싼 Cu로 대체함으로써 가격을 낮출 수 있는 장점이 있다. 실험에 사용된 Si 웨이퍼 특성은 $156{\times}156$ mm2, 200 ${\mu}m$, 0.5-3.0 ${\Omega}{\cdot}cm$ and p-type 웨이퍼를 사용하였다. 웨이퍼는 표면조직화, p-n접합 형성, 반사방지막 코팅을 하였으며 스크린 프린팅 방법을 이용해 전 후면 전극을 인쇄하고 열처리 과정을 통해 전극을 형성하였다. 이 후 전면에 Cu도금을 실행하여 태양전지를 완성하였다. 완성된 태양전지는 솔라 시뮬레이터 및 TLM패턴을 이용하여 전기적 특성을 분석하였으며, SEM과 linescan, 광학현미경 등을 이용하여 전극을 분석하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1100-1101
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• 2008

After lamination process, Isc is increased by sheet reflection. This paper presents the electrical output characteristics by back sheet reflection. The experiments was conducted by using single crystalline and multi crystalline PV module. The reflection area of single crystalline PV module is larger than multi one due to the difference of solar cell manufacturing. The experiments show that the increased performance ratio of single crystalline PV module output power is 1.55% rather than that of multi crystalline PV module output power is 1.13%. In addition, it is expected that the output power of single one rather than multi-one is increased by the lower temperature when the PV module is installed outside. The results can be reconsidered by the test material and test process. Back sheet used for humidity prevention makes PV module output power increasing.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.147-148
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• 2007

Dye-sensitized solar cell using conversion of solar energy to electrical energy appeared that which solves a environmental matter. The dye-sensitized solar cell uses nano-crystalline oxide semiconductor for absorbing dye. The $TiO_2$ is used most plentifully. The efficiency of the dye-sensitized solar cell changes consequently in the particle size, morphology, crystallization and surface state of the $TiO_2$. In this paper, we report The effect of titania$(TiO_2)$ thickness on the performance of dye-sensitized solar cells. Using doctor blade method, It produced the thickness of the $TiO_2$ with $7\;{\mu}m,\;10\;{\mu}m,\;13\;{\mu}m$. The efficiency was the best from $10{\mu}m$. It had relatively low efficiency on the thickness from $7\;{\mu}m\;to\;13\;{\mu}m$. The reason why it presents low efficiency on $7\;{\mu}m$ thickness is that excited electrons can not be delivered enough due to thin thickness of $7\;{\mu}m\;TiO_2$. And The reason why it presents low efficiency on $13\;{\mu}m$ thickness is that thick $13\;{\mu}m\;TiO_2$ can not penetrate the sunlight enough.

• 한국결정성장학회지
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• 제23권3호
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• pp.119-123
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• 2013

Most of the world's solar cells in photovoltaic industry are currently fabricated using crystalline silicon. Czochralski-grown silicon crystals are more expensive than multicrystalline silicon crystals. The future of solar-grade Czochralski-grown silicon crystals crucially depends on whether it is usable for the mass-production of high-efficiency solar cells or not. It is generally believed that the main obstacle for making solar-grade Czochralski-grown silicon crystals a perfect high-efficiency solar cell material is presently light-induced degradation problem. In this work, the substitution of boron with gallium in p-type silicon single crystal is studied as an alternative to reduce the extent of lifetime degradation. The diamond-wire sawing technology is employed to slice the silicon ingot. In this paper, the quality of the diamond wire-sawn gallium-doped silicon wafers is studied from the chemical, electrical and structural points of view. It is found that the characteristic of gallium-doped silicon wafers including texturing behavior and surface metallic impurities are same as that of conventional boron-doped Czochralski crystals.

• 전자공학회논문지A
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• 제29A권2호
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• pp.55-62
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• 1992

Polycrystalline silicon ingots were manufactured using the casting method for polycrystalline silicon solar cells. These ingots were cut into wafers and ten n$^{+}$p type solar cells were made through the following simple process` surface etching, n$^{+}$p junction formation, metalization and annealing. For the grain boundary passivation, the samples were oxidized in O$_2$ for 5 min. at 80$0^{\circ}C$ prior to diffusion in Ar for 100 min. at 95$0^{\circ}C$. The conversion efficiency of polycrystalline silicon solar cells made from these wafers showed about 70-80% of those of the single crystalline silicon solar cell and superior conversion efficiency, compared to those of commercial polycrystalline wafers of Wacker Chemie. The maximum conversion efficiency of our wafers was indicated about 8%(without AR coating) in spite of such a simple fabrication method.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 추계학술대회 초록집
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• pp.47.2-47.2
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• 2011

High-efficient transparent conductive oxide (TCO) film-embedding Si heterojunction solar cells were fabricated. An improved crystalline indium-tin-oxide (ITO) film was grown on an Al-doped ZnO (AZO) template upon hetero-epitaxial growth. This double TCO-layered Si solar cell provided significantly enhanced efficiency of 9.23 % as compared to the single TCO/Si devices. The effective arrangement of TCO films (ITO/AZO) provides a good interface, resulting in the enhanced photovoltaic performances. It discusses TCO film arrangement scheme for efficient TCO-layered heterojunction solar cells.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.209-209
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• 2012

High-efficient transparent conductive oxide (TCO) film-embedding Si heterojunction solar cells were fabricated. An additional doping was not applied for heterojunction solar cells due to the spontaneous junction formation between TCO films and an n-type Si substrate. Three different TCO coatings were formed by sputtering method for an Al-doped ZnO (AZO) film, an indium-tin-oxide (ITO) film and double stacks of ITO/AZO films. An improved crystalline ITO film was grown on an AZO template upon hetero-epitaxial growth. This double TCO films-embedding Si heterojunction solar cell provided significantly enhanced efficiency of 9.23% as compared to the single TCO/Si devices. The effective arrangement of TCO films (ITO/AZO) provides benefits of a lower front contact resistance and a smaller band offset to Si leading enhanced photovoltaic performances. This demonstrates a potential scheme of the effective TCO film-embedding heterojunction Si solar cells.

• 반도체디스플레이기술학회지
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• 제17권3호
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• pp.10-16
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• 2018

In silicon crystalline PV (Photo Voltaic) industry, PV module or panel electric power is directly related to the companies' profit. Thus, many PV companies have invested and focused on R&D activities to get the higher module power. The main BOM (Bills of Material) on the module consists of PV solar cell, ribbon, EVA (Ethylene-Vinyl Acetate copolymer), glass and back sheet. Based on consistent research efforts on enhancing module power using BOM, there have been increase of around 5 watt per module every year as results. However, there are lack of studies related to enhancing accuracy of measurement. In this study, the enhancing on the metrology is investigated and the improvement shows actually contribution to company's profit. Especially, the measurement issues related to heat and to quasi state of bandgap diagram by EL(Electro Luminescence) are described in this study.

• Current Photovoltaic Research
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• 제5권2호
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• pp.63-67
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• 2017

Aluminum oxide ($Al_2O_3$) film deposited by atomic layer deposition (ALD) is known to supply excellent surface passivation properties on crystalline Si surface. The quality of passivation layer is important for high-efficiency silicon solar cell. double-layer structures have many advantages over single-layer materials. $Al_2O_3/SiN_X$ passivation stacks have been widely adopted for high- efficiency silicon solar cells. The first layer, $Al_2O_3$, passivates the surface, while $SiN_X$ acts as a hydrogen source that saturates silicon dangling bonds during annealing treatment. We explored the properties on passivation film of $Al_2O_3/SiN_X$ stack layer with changing the conditions. For the post annealing temperature, it was found that $500^{\circ}C$ is the most suitable temperature to improvement surface passivation.

• Current Photovoltaic Research
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• 제7권4호
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• pp.111-120
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• 2019

The output power of a crystalline silicon (c-Si) photovoltaic (PV) module is not directly the sum of the powers of its unit cells. There are several losses and gain mechanisms that reduce the total output power when solar cells are encapsulated into solar modules. Theses factors are getting high attention as the high cell efficiency achievement become more complex and expensive. More research works are involved to minimize the "cell-to-module" (CTM) loss. Our paper is aimed to focus on electrical losses due to interconnection and mismatch loss at PV modules. Research study shows that among all reasons of PV module failure 40.7% fails at interconnection. The mismatch loss in modern PV modules is very low (nearly 0.1%) but still lacks in the approach that determines all the contributing factors in mismatch loss. This review paper is related to study of interconnection loss technologies and key factors contributing to mismatch loss during module fabrication. Also, the improved interconnection technologies, understanding the approaches to mitigate the mismatch loss factors are precisely described here. This research study will give the approach of mitigating the loss and enable improvement in reliability of PV modules.