• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.115.1-115.1
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• 2011

최근 기본적인 pin 구조의 박막 cell 에서 i layer를 최적화 시키는 방안으로 double layer 구조가 많이 연구되고 있다. 본 연구에서는 ASA(Advanced Semicon ductor Analysis) simulation을 이용하여 i-double layer 최적화에 대한 연구를 진행해 보았다. 두께 150/150nm의 i double layer의 band gap 가변을 한 simulation 결과를 보았을 때, p쪽의 band gap이 상승하면서 intrinsic layer 내의 field가 증가하여 recombination center가 감소하였으나 FF의 감소가 있었다. n쪽의 band gap을 상승 시켰을때 n/i 쪽 field 증가로 Voc가 상승되어 초기 효율이 증가하였으나 intrinsic layer내의 field가 감소하여 recombination center가 오히려 증가하였다. 결과적으로 electric field와 효율을 동시에 고려했을 때 두께 300nm, 1.75의 band gap을 가지는 single layer 보다 150/150nm두께에 1.8/1.7 또는 1.8/1.75의 bandgap을 가지는 double layer를 사용하였을 때 보다 높은 효율을 얻을 수 있었다.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.22 no.2
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• pp.65-72
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• 2012

Aluminum induced crystallization of amorphous silicon was attempted by the aluminum substrate. To avoid the layer exchange between silicon and aluminum layer, Ni layer was deposited between these two layers by sputtering. To obtain the bigger grain of the crystalline silicon, wet blasted silica layer was employed as windows between the nickel and a-Si layer. Ni obtained after the annealing treatment at $520^{\circ}C$ was found to be a promising material for the diffusion barrier between silicon and aluminum. One way to obtain bigger grain of crystalline silicon layer applicable to solar cell of higher performance was envisioned in this investigation.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.10
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• pp.1019-1023
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• 2012

In this research, a novel direct-aluminum-heating-induced crystallization method was developed for the purpose of application to solar cells. By applying a constant current of 3 A to an aluminum thin film, a 200-nm-thick amorphous silicon (a-Si) thin film with a size of $1cm{\times}1cm$ can be crystallized into a polycrystalline silicon (poly-Si) thin film within a few tens of seconds. The Raman spectrum analysis shows a peak of 520 $cm^{-1}$, which verifies the presence of poly-Si. After removing the aluminum layer, the poly-Si thin film was found to be porous. SIMS analysis showed that the porous poly-Si thin film was heavily p-doped with a doping concentration of $10^{21}cm^{-3}$. Thermal imaging shows that the crystallization from a-Si to poly-Si occurred at a temperature of around 820 K.

• Solar Energy
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• v.8 no.1
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• pp.68-73
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• 1988

In the glass/TCO/p-i-n a-Si/Al type of amorphous silicon solar cell, the effects on solar cell efficiency and metastability for the various kinds of TCO analyzed by SAM and ESCA, which was used to measure the diffusion profiles of In and Sn and the Fermi energy shifts in the TCO/p interface respectively. Indium which diffused into a-Si p-layer did not have any significant effects on the Fermi level shift of p-layer when the content of $B_2H_6/SiH_4$ in p-layer was at 1 gas%. The cell fabricated on $SnO_2$ turned out to have the best cell photovoltaic characteristics. ITO fabricated by electron beam deposition system, which was shown to have the greatest rate of diffusion of Indium in ITO/p interface produced the worst metastability among the cells tested.

• Solar Energy
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• v.7 no.1
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• pp.30-34
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• 1987

Experimental results are discussed concerning temperature effects from $25^{\circ}C$ to $100^{\circ}C$ on amorphous silicon solar cells. N-I-P hydrogenated amorphous silicon solar cells are fabricated on stainless steel and indium tin oxide glass substrates. The open circuit voltage, short circuit current, fill factor and conversion efficiency have been measured under AM1 condition as a function of temperature. The open circuit voltage decreased by $2.6mV/^{\circ}C$ while the short circuit current increases with increased temperature. The conversion efficiency is almost independent of temperature which is contrary to widely using single crystalline solar cells of which efficiencies decrease with increasing temperature.

• Solar Energy
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• v.7 no.1
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• pp.35-41
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• 1987

This paper presents a comprehensive computer simulation of hydrogenated amorphous p-i-n silicon solar cells. The physical mechanism governing solar cell operation has been modeled and solved numerically by Runge-Kutta-Gill method. Effects of gap state density, dopant impurity, diffusion length and interface recombination velocity on solar cell performance are investigated. Numerical results show that the electric field in i-region is not uniform but depends strongly on voltage and position. A rather poor fill factor may be due to the electric field variation and short diffusion length. It is found out that the life time should be improved in order to increase a fill factor and a conversion efficiency.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.450-451
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• 2008

Amorphous silicon Solar cell has n-i-p structure in general, and each layer's thickness and doping concentration are very important factors which are as influential on efficiency of salar cell. Using AFORS HET simulation to get the high efficiency, by adjusting n layer's thickness and doping concentration, p layer's doping concentration. The optimized values are a-Si:H(n)'s thickness of 1nm, a-Si:H(n)r's doping concentration of $2\times10^{20}cm^{-3}$, a-Si:H(p+)r's doping concentration of $1\times10^{19}cm^{-3}$. After optimization, the solar cell shows $V_{oc}$=679.5mV, $J_{sc}$=39.02mA/$cm^2$, FF=83.71%, and a high Efficiency=22.21%. Though this study, we can use this study for planning or manufacturing solar cell which has high efficiency.

• Solar Energy
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• v.20 no.1
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• pp.11-20
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• 2000

To get more insight into the buffering effects of the p-${\mu}c$-Si:H Inserted at the p-a-SiC:H/i-a-Si:H interface, we present a systematic numerical simulation using Gummel-Schafetter method. The reduced recombination loss at the p/i interface due to a constant bandgap buffer is analysed in terms of the variation of the p/i Interface region with a short lifetime and the characterisitics of the buffer such as mobility bandgap, acceptor concentration, and D-state density. The numerical modeling on the constant bandgap buffer demonstrates clearly that the buffering effects of the thin p-${\mu}c$-Si:H originate from the shrinkage of highly defective region with a short lifetime in the vicinity of the p/i interface.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.910-912
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• 2009

투명전극은 비저항이 $1{\times}10^{-3}{\Omega}/cm$이하, 면저항이 $10^3{\Omega}/sq$이하로 전기전도성이 우수하고 380에서 780nm의 가시광선 영역에서의 투과율이 80%이상이라는 두 가지 성질을 만족시키는 박막이다. 기존의 평판디스플레이의 경우, 금속 산화물 투명전극이 진공 증착 공정을 통해 도포된 유리기판상의 각 화소를 포토리소그래피 공정으로 제조된 박막트랜지스터(TFT : Thin Film Transistor)로 제어함으로써 화상을 구현한다. 본 연구에서는 스퍼터링 진공 증착 장치를 이용하여 투명 도전막(ITO: Indium Tin Oxide)을 제작하고 제작된 ITO 박막의 광 및 전기 그리고 물성적 특성을 조사하여 최상의 공정 조건을 확립하였다. a-Si:H 박막위에 형성되는 ITo 박막은 a-Si:H 박막의 특성상 온도 및 스퍼터링 전력에 대한 연구가 주요 문제이다. 본 실험에서는 $In_2O_3:SnO_2$의 조성비는 90:10 wt% 인 타겟의 특성이 우수하였고, $Ar:O_2$의 분압비는 100:1 및 42:8 의 조건이 적당하였으며, 온도는 $200^{\circ}C$ 가장 우수한 특성을 얻을 수 있었다. $200^{\circ}C$ 는 비정질 실리콘의 성능에 좋은 영향을 미치는 온도이며, 알려진 것과 같이 $23^{\circ}C$ 즉 실온의 경우에 비해 막의 균질성 및 특성이 우수 한 것을 알 수 있었다. 본 연구에서 제작한 박막은 광 투과도가 90% 이상, 비저항이 $300{\mu}{\Omega}cm$ 이하의 특성을 갖게되어 이미지센서, 태양전지, 액정 텔레비젼등 빛의 통과와 전도성등 두가지 특성에 동시에 만족 될만한 성능을 가질 수 있음을 확인하였다.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.2
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• pp.354-356
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• 2017

We focused on light management technology in amorphous silicon solar cells to suppress increase in absorber thickness for improving power conversion efficiency (PCE). $MgF_2$ and $TiO_2$ anti-reflection layers were coated on both sides of Asahi VU ($glass/SnO_2:F$) substrates, which contributed to increase in PCE from 9.16% to 9.81% at absorber thickness of only 150 nm. Also, we applied very thin $MgF_2$ as a rear reflector at n-type nanocrystalline silicon oxide/Ag interface to boost photocurrent. By reinforcing rear reflection, we could find the PCE increase from 10.08% up to 10.34% based on thin absorber about 200 nm.