• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2007년도 추계학술대회 논문집
• /
• pp.233-233
• /
• 2007

• 한국재료학회:학술대회논문집
• /
• 한국재료학회 2010년도 춘계학술발표대회
• /
• pp.35.1-35.1
• /
• 2010

The Cu(In,Ga)Se2(CIGS) thin film solar cells have been achieved until almost 20% efficiency by NREL. These solar cells include chemically deposited CdS as buffer layer between CIGS absorber layer and ZnO window layer. Although CIGS solar cells with CdS buffer layer show excellent performance, many groups made hard efforts to overcome its disadvantages in terms of high absorption of short wavelength, Cd hazardous element. Among Cd-free candidate materials, the CIGS thin film solar cells with Zn compound buffer layer seem to be promising with 15.2%(module by showa shell K.K.), 18.6%(small area by NREL). However, few groups were successful to report high-efficiency CIGS solar cells with Zn compound buffer layer, compared to be known how to fabricate these solar cells. Each group's chemical bah deposition (CBD) condition is seriously different. It may mean that it is not fully understood to grow high quality Zn compound thin film on the CIGS using CBD. In this study, we focused to clarify growth mechanism of chemically deposited Zn compound thin film on the CIGS, especially. Additionally, we tried to characterize junction properties with unfavorable issues, that is, slow growth rate, imperfect film coverage and minimize these issues. Early works reported that film deposition rate increased with reagent concentration and film covered whole rough CIGS surface. But they did not mention well how film growth of zinc compound evolves homogeneously or heterogeneously and what kinds of defects exist within film that can cause low solar performance. We observed sufficient correlation between growth quality and concentration of NH3 as complex agent. When NH3 concentration increased, thickness of zinc compound increased with dominant heterogeneous growth for high quality film. But the large amounts of NH3 in the solution made many particles of zinc hydroxide due to hydroxide ions. The zinc hydroxides bonded weakly to the CIGS surface have been removed at rinsing after CBD.

• Transactions on Electrical and Electronic Materials
• /
• 제18권2호
• /
• pp.93-96
• /
• 2017

The structural, electrical and optical properties of Ti thin films fabricated by dual magnetron sputtering were investigated under various film thicknesses. The fabricated Ti thin films exhibited uniform surfaces, crystallinity, various grain sizes, and with various film thicknesses. Also, the crystallinity and grain size of the Ti thin films increased with the increase of film thickness. The electrical properties of Ti thin films improved with the increase of film thickness. The results showed that the performance of TCO-less DSSC critically depended on the film thickness of the Ti working electrodes, due to the conductivity of Ti thin film. However, the maximum conversion efficiency of TCO-less DSSC was exhibited at the condition of 100 nm thickness due to the surface scattering of photons caused by the variation of grain size.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
• /
• pp.85.1-85.1
• /
• 2010

$Cu(In,Ga)Se_2$ (CIGS) thin film solar cell is currently 19.5% higher efficiency and developing a large area technology. The structure of CIGS solar cell that make five unit layers as back contact, light absorption, buffer, front transparent conducting electrode and antireflection to make them sequentially forming. Materials and various compositions of thin film unit which also manufacture a variety method used by the physical and chemical method for CIGS solar cell. The construction and performance test of evaporator for CIGS thin film solar cell has been done. The vapor pressures were changed by using vapor flux meter. The vapor pressure were copper (Cu) $2.1{\times}10^{-7}{\sim}3.0{\times}10^{-7}$ Torr, indium (In) $8.0{\times}10^{-7}{\sim}9.0{\times}10^{-7}$ Torr, gallium (Ga) $1.4{\times}10^{-7}{\sim}2.8{\times}10^{-7}$ Torr, and selenium (Se) $2.1{\times}10^{-6}{\sim}3.2{\times}10^{-6}$ Torr, respectively. The characteristics of the CIGS thin film was investigated by using X-ray diffraction (XRD), scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) and photoluminescence (PL) spectroscopy using a He-Ne laser. In PL spectrum, temperature dependencies of PL spectra were measured at 1137 nm wavelength.

• Current Photovoltaic Research
• /
• 제12권2호
• /
• pp.41-47
• /
• 2024

CIGS solar cells are thin film solar cells that have excellent light absorption coefficient and can be manufactured with high efficiency through the use of low materials. In Korea, they must pass KS certification for home and commercial installation. KS C 8562 is a standard for evaluating the durability of CIGS and thin film amorphous silicon solar modules and deals with contents such as light, temperature, humidity, and mechanical durability. Unlike general crystalline silicon solar modules, the CIGS solar module has a different behavior of output change through these environmental tests, so if it shows 90% or more of the rated output suggested by the manufacturer after the final test, it is judged to be a suitable product. In this paper, the output before and after individual tests was measured through the test method of KS C 8562 to observe the output change and to discover the vulnerabilities of the CIGS solar module when exposed to various environments. Through this, it was confirmed that humidity exposure was the most vulnerable and that it had output recovery characteristics for light (visible light and ultraviolet rays). This study attempted to present the output behavior characteristics and data of the CIGS module at the time when the high efficiency thin film photovoltaic module market is expected to be created in the future.

• Current Photovoltaic Research
• /
• 제2권3호
• /
• pp.95-102
• /
• 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.

• 한국콘텐츠학회논문지
• /
• 제22권7호
• /
• pp.55-62
• /
• 2022

페로브스카이트 태양전지는 4차 산업혁명으로 사물인터넷, 가상환경 등의 증가에 따른 전력 수요가 급증하면서 점진적으로 고갈되어가는 석유, 석탄, 천연가스 등의 화석연료를 대체할 태양에너지, 풍력, 수력, 해양에너지, 바이오에너지, 수소에너지 등의 신재생 에너지 분야에서 연구가 활발한 부분이다. 페로브스카이트 태양전지는 페로브스카이트 구조를 가진 유-무기 하이브리드 물질을 사용하는 태양전지 소자로 고효율, 저가의 용액 및 저온 공정으로 기존의 실리콘 태양전지를 대체할 수 있는 장점들이 있다. 기존의 경험적 방법으로 예측한 광흡수층 박막을 최적화하기 위해서 소자 특성 평가를 통해 신뢰도를 검증해야 한다. 그러나 광흡수층 박막 소자 특성 평가 비용이 많이 소요되므로 시험 횟수에 제약이 따른다. 이러한 문제점을 해결하기 위하여 광흡수층 박막 최적화의 보조 수단으로 머신러닝이나 인공지능 모델을 이용하여 명확하고 타당한 모델의 개발과 적용 가능성이 무한하다고 본다. 이 연구에서는 페로브스카이트 태양전지의 광 흡수층 박막 최적화를 추정하기 위하여 서포트 벡터 머신의 선형 커널, 가우시안 커널, 비선형 다항식 커널, 시그모이드 커널의 회귀분석 모델을 비교하여 커널 함수별 정확도 차이를 검증하였다.

• Bulletin of the Korean Chemical Society
• /
• 제31권10호
• /
• pp.2909-2912
• /
• 2010

Hydrogenated microcrystalline silicon (${\mu}c$-Si:H) thin film for solar cells is prepared by plasma-enhanced chemical vapor deposition and physical properties of the ${\mu}c$-Si:H p-layer has been investigated. With respect to stable efficiency, this film is expected to surpass the performance of conventional amorphous silicon based solar cells and very soon be a close competitor to other thin film photovoltaic materials. Silicon in various structural forms has a direct effect on the efficiency of solar cell devices with different electron mobility and photon conversion. A Raman microscope is adopted to study the degree of crystallinity of Si film by analyzing the integrated intensity peaks at 480, 510 and $520\;cm^{-1}$, which corresponds to the amorphous phase (a-Si:H), microcrystalline (${\mu}c$-Si:H) and large crystals (c-Si), respectively. The crystal volume fraction is calculated from the ratio of the crystalline and the amorphous phase. The results are compared with high-resolution transmission electron microscopy (HR-TEM) for the determination of crystallinity factor. Optical properties such as refractive index, extinction coefficient, and band gap are studied with reflectance spectra.

• 한국진공학회지
• /
• 제19권4호
• /
• pp.275-280
• /
• 2010

MOCVD (Metal-Organic Chemical Vapor Deposition) 장비를 사용하여 BZO (boron doped zinc oxide, ZnO:B) 박막을 증착하고 수소 플라즈마 처리공정을 진행하였다. 본 연구는 수소 플라즈마 처리된 BZO 박막에 산소 플라즈마 재처리를 진행하여 BZO 박막의 특성 변화를 분석하였다. 그 결과 BZO 박막 성장은 (100), (101), (110)을 확인하였고, 산소 플라즈마 재처리에 의하여 일함수와 표면 저항이 증가하였다. 수소 플라즈마 처리만을 진행한 BZO 박막과 산소 플라즈마 재처리 공정을 진행한 BZO 박막의 300~1,100 nm에서 가중치 투과율은 86%로 변화하지 않았으며, 가중치 산란도는 12%에서 15%로 증가하였다.

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