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1.
The availability and cost of materials, especially of indium can be a limiting factor as chalcopyrite based thin-film solar cells advance in their commercialization. The required amounts of metals can be lowered by using thinner films. When the thickness of the film decreases, there is possibility of remaining only in the small grain region because the coalescence of grains does not have an opportunity to enhance the grain size to the maximum. Solar cell performance in smaller grain chalcopyrite absorber deteriorates due to larger fraction of grain boundaries. Efforts are being made to reduce the thickness while maintaining the comparable performance. This work presents a study of preparation, morphology and other material properties of CIGS2 absorber layers with decreasing thicknesses up to 1.2 μm and its correlation with the device performance. Encouraging results were obtained demonstrating that reasonable solar cell efficiencies (>10%) can be achieved even for thinner CIGS2 thin-film solar cells. 相似文献
2.
Ma?gorzata Igalson Pawe? Zabierowski Aleksander Urbaniak William N. Shafarman 《Solar Energy Materials & Solar Cells》2009,93(8):1290-1295
Many electrical characteristics of Cu(In,Ga)Se2-based solar cells, including current-voltage characteristics, are affected by specific properties of negative-U defects in the absorber. We present these characteristics and discuss them in the framework of a VSe-VCu defect model proposed by Lany and Zunger. We show how these defects influence photocarrier transport and the dominant recombination mechanism, and hence also the photovoltaic parameters of the cells. Numerical simulations validating our approach will also be presented. 相似文献
3.
Low cost processing of CIGS thin film solar cells 总被引:2,自引:0,他引:2
A set of low cost techniques with realistic potential for direct manufacturing costs reduction were developed in the last five years while the industrial Cu(In,Ga)Se2 (CIGS) solar cell production is based on vacuum processes, which require high initial investment into production machines. The common properties of these low cost techniques are the use of simple and fast non-vacuum deposition methods and the prefixing of the film-composition on a molecular level in a precursor layer, which is chemically and thermally treated to form a high quality CIGS film. The paste coating approaches use premixed inks which are applied by doctor-blade coating to yield solar cell efficiencies of 13.6%, with the potential to reach 15% and more in the next years. The choice of the precursor material has to be made with respect to the used selenization conditions to avoid detrimental impurity phases. A new precursor material is discussed, which allows fast conversion in selenium atmosphere and was used to produce solar cells with 6.7% efficiency. The CIGS film thickness has to be increased for complete absorption of the incident light. 相似文献
4.
High-efficiency silicon space solar cells 总被引:1,自引:0,他引:1
Akio Suzuki 《Solar Energy Materials & Solar Cells》1998,50(1-4):289-303
SHARP's activities on Si solar cells developments and features of Si solar cells for space use in comparison with GaAs solar cells are presented. Two types of high-efficiency silicon solar cells and the same kinds of high-efficiency solar cells with integrated bypass function (IBF cells) were developed and qualified for space applications. The NRS/LBSF cells and NRS/BSF cells showed an average of 18% and 17% efficiencies, respectively, at AMO and 28°C conditions. The IBF cells have P+N+ diodes on the front surface to protect itself from reverse voltage due to shadowing. The designs and features of these solar cells are presented. The radiation tests results of these solar cells are also presented. The NRS/BSF cells showed lower degradation rate compared to conventional BSFR cells with the same thickness (100 μm). But the NRS/LBSF cells showed a higher degradation rate than the BSFR cells. The IBF cells showed almost the same radiation characteristics as the same kinds of cells without IBF. The results of radiation tests on these high-efficiency solar cells and the discussions about the radiation characteristics of them are presented. In the last section, the future silicon solar cell development plan is discussed. 相似文献
5.
Band gap grading is able to improve the performance of CIGS solar cells. In order to get a better understanding of the parameters influencing the effect of a grading, a closed form analytical expression of the current density is derived. The advantages and drawbacks of this analytical expression with respect to numerical simulation results are assessed. The analytical analysis has limited validity due to restrictions on the absorption characteristic and on the recombination in the space charge layer. Nevertheless it leads to good results, it has the advantage of being faster than numerical simulations and it clarifies the interrelation of the meaningful parameters. 相似文献
6.
The present contribution reports on the performances of ultra thin chalcopyrite Cu (In,Ga) Se (CIGS) solar cells. An alternative ZnO/CdS/CIGS/Si structure has been proposed using solar cell capacitance simulator (SCAPS). The main idea behind this analysis is the improvement of the device efficiency using materials cheaper than conventional CIGS. For that purpose, a 1 μm of a new layer p-Si has been added. Various thicknesses of CIGS absorber layer ranging from 0.1 to 1 μm have been used. Our findings showed that the increase of the absorber layer thickness leads to the improvement of the performance of the new CIGS solar cells. It was found that the best structure must have a window layer ZnO, a buffer layer (CdS), an absorbent layer (CIGS) and a Si layer with thicknesses of 0.02, 0.05, 1 and 1 μm, respectively. Cells with these features give conversion efficiency of 21.3%. The present results showed that the new ultra thin CIGS solar cells structure has performance parameters that are comparable to those of the conventional ones with reduced cost. 相似文献
7.
Susanne Siebentritt Timon Kampschulte Andreas Bauknecht Ulf Blieske Wolfgang Harneit Ulrich Fiedeler Martha Lux-Steiner 《Solar Energy Materials & Solar Cells》2002,70(4):447-457
ZnSe buffer layers for Cu(ln,Ga)Se2/buffer/ZnO solar cells have been prepared by metal organic chemical vapor deposition (MOCVD). Using photoassisted MOCVD, deposition temperatures down to 265°C are possible. It is shown that deposition temperatures well below 300°C are essential as well as deposition times not much longer than 3 min. Higher temperatures and longer deposition times lead to absorber degradation. With optimized buffer deposition efficiencies of 11% have been obtained on CIGS absorbers from the Siemens pilot production line. 相似文献
8.
This paper describes the technological status of and some challenges in the manufacturing of Cu(In,Ga)Se2 (CIGS)-based solar cells on flexible polymer and metal substrates. Substrate characteristics such as thermal expansion properties and stability, surface roughness, or substrate composition, strongly influence growth and properties of the following layers. For example, adhesion failure, cracking, or contamination by diffusion of impurities from the substrate may occur with some substrates. Aspects of (external) sodium incorporation into CIGS are discussed for high and low CIGS deposition temperature. Low-temperature deposition processes are particularly important when polyimide substrates are used. The electrical insulation of metal foils by dielectric barriers (e.g. SiOx or Al2O3) allows the fabrication of monolithically integrated modules. A soft and selective patterning technique based on laser scribing and mask-free photolithography is described. Working modules as large as 20 cm × 30 cm were achieved with these methods. 相似文献
9.
Neelkanth G. Dhere Ankur A. Kadam Sachin S. Kulkarni Sachin M. Bet Anant H. Jahagirdar 《Solar Energy》2004,77(6):697-703
In earlier research, conversion efficiency of 10.4% (AM1.5) and 9.9% (AM0) has been achieved on small area CuInxGa1−xS2 (CIGS2) solar cell on 127 μm thick stainless steel substrate. The area of research is mainly focused on studying CIGS2 thin films as solar cell absorber material and growing high efficiency cells on ultralightweight and flexible metallic foils such as 127 μm thick stainless steel and SiO2 coated 25 μm thick Ti foils. This paper presents the scaling up process of CIGS2 thin film substrate from 2.5 × 2.5 cm2 to 10 × 10 cm2. Initial scaling up efforts focused on achieving uniform thickness and stress-free films. Process of scaling up consisted of refurbishment of selenization/sulfurization furnace, design and fabrication of scrubber and enlargement of new CdS deposition setup. The scaling up from 2.5 × 2.5 cm2 to 10 × 10 cm2 substrate size has laid the foundation for PV Materials Lab of Florida Solar Energy Center becoming the nucleus of a pilot plant. 相似文献
10.
Woo-Seok JeongJin-Wook Lee Soonil JungJae Ho Yun Nam-Gyu Park 《Solar Energy Materials & Solar Cells》2011,95(12):3419-3423
A tandem solar cell is constructed by series connection of a semi-transparent dye-sensitized solar cell (DSSC) as a top cell and a Cu(In, Ga)Se2 (CIGS) solar cell as a bottom cell, where the isolated DSSC and CIGS cells show the conversion efficiency of 8.27% and 11.71%, respectively. The DSSC/CIGS tandem cell exhibits the improved conversion efficiency of 12.35% with photocurrent density of 14.1 mA/cm2, open-circuit voltage of 1.435 V and fill factor of 0.61. External quantum efficiency (EQE) of the tandem cell is investigated under DC and AC modes. EQE of the isolated DSSC and CIGS cell can be measured by either DC mode or AC mode, whereas EQE for the tandem cell is detected only under AC mode with bias light. Bias light intensity is found to play the crucial role in determining the precise EQE of the tandem cell. At the given chopping frequency as low as 10 Hz, the measured EQE at bias light corresponding to 1 sun intensity is consistent with the simulated EQE data. 相似文献
11.
We have proposed a novel laser-assisted-deposition (LAD) process for improving the crystalline quality of CIGS thin films and cell performance. The influences of laser power, Ga content in CIGS, substrate temperature, and photon energy of laser on CIGS thin films and solar cells have been investigated. In the LAD process a pulsed excimer laser and a pulsed Nd:YAG laser were irradiated onto the substrate surface during CIGS deposition by the three-stage process. The crystalline quality of CIGS thin films and cell performance, particularly open-circuit-voltage, improved by LAD process for all ranges of Ga content and at substrate temperature ranges of 400-550 °C. It was also found that the laser irradiation enhanced the diffusion of Ga into CIGS even at low substrate temperatures, which strongly affects the formation of double-graded bandgap. The PL decay time of LAD-CIGS solar cells was much longer than that of the fabricated by the three-stage process, which implies the reduced defects in CIGS absorber layer. The improved thin-film quality and cell performance became noticeable only when the laser wavelength was shorter than 266 nm (4.66 eV of photon energy). This result strongly suggests that the impacts of pulsed-laser irradiation are dominated by photon-energy rather than thermal-energy. 相似文献
12.
Vignesh Gowrishankar Christine K. Luscombe Michael D. McGehee Jean M.J. Frchet 《Solar Energy Materials & Solar Cells》2007,91(9):807-812
The use of a semiconducting polymer as a buffer layer replacement for CdS in traditionally all-inorganic copper–indium–gallium–diselenide (CIGS)-based solar cells is reported. The semiconducting polymer used is poly(benzimidazobenzophenanthroline) (BBL), which has physical and electronic properties that facilitate a suitable junction between the CIGS and the top electrode. We report on the fabrication, physical properties and photovoltaic characteristics of such Cd-free organic–inorganic devices, which have 6% power-conversion efficiencies. 相似文献
13.
Neelkanth G. Dhere 《Solar Energy Materials & Solar Cells》2011,95(1):277-280
Photovoltaics cost has been declining following a 70% learning curve. Now the challenge is to bring down the cost of solar electricity to make it competitive with conventional sources within the next decade. In the long run, the module efficiencies tend to reach 80% of the champion cell efficiencies. Using a semiempirical methodology, it has been shown earlier that while the triple junction a-Si:H thin film technology is competitive, CIGS and CdTe thin film module technologies are highly competitive and presently offer the best approach for significantly exceeding the cost/performance levels of standard and non-standard crystalline Si PV technologies. Since 2006, the production of thin film solar cell in the U.S. has surpassed that of c-Si. At present, the production of CIGS PV modules lags considerably behind that of CdTe PV modules. This is mainly because of its complexity. Scale-up issues related to various CIGS preparation technologies such as co-evaporation, metallic precursor deposition by magnetron sputtering and non-vacuum techniques such as ink-jet printing, electroplating or doctor-blade technology followed by their selenization/sulfurization are discussed so as to assist the CIGS technology to attain its full potential. Besides the welcome announcements of large volume production, it is essential to achieve the production cost below $1/Wp in the near term and attain production speeds comparable to CdTe production speeds. Comparable production speeds are expected to be achieved within the next decade. This will enable reduction of CIGS module production costs to ∼65¢/Wp that would be comparable to the CdTe module projected production cost. Additionally CIGS will have a higher efficiency premium. 相似文献
14.
Surface sulfurization of Cu(In,Ga)Se2 (CIGS) thin films was carried out using two alternative techniques that do not utilize toxic H2S gas; a sequential evaporation of In2S3 after CIGS deposition and the annealing of CIGS thin films in sulfur vapor. A Cu(In,Ga) (S,Se)2 thin layer was grown on the surface of the CIGS thin film after sulfurization using In2S3, whereas this layer was not observed for CIGS thin films after sulfurization using sulfur vapor, although a trace quantity of S was confirmed by AES analysis. In spite of the difference in the surface modification techniques, the cell performance and process yield of the ZnO:Al/CdS/CIGS/Mo/glass thin-film solar cells were remarkably improved by using both surface sulfurization techniques. 相似文献
15.
It is a big challenge for all thin-film PV technologies to exhaust the high potential of cost reduction, which is beyond controversy. For Cu(In,Ga)Se2 (CIGS) based PV modules, which have the highest efficiency potential among thin-film technologies, a productive industrial process technology has been not demonstrated up to now.In the ZSW line, the maximum efficiency for 30 cm×30 cm was close to 13% (11% in average) at a high yield. In several batches, hundreds of modules were processed and characterized. Process statistics are described.First results of film depositions and processing on large area from the Wuerth Solar pilot line are presented. The concept for the integrated module line will be discussed. First modules in the square meter range are demonstrated with efficiencies >8%. 相似文献
16.
Cadmium telluride is a promising photovoltaic material for thin-film solar cells. However, further improvements on performance and reproducibility of devices have been limited by the conventional SnO2/poly-CdS/poly-CdTe device structure used for more than 30 years. In this paper, we review partial R&D approaches at NREL to understand the issues related to the conventional device structure and to develop several novel materials and a modified device structure for minimizing these issues. We have achieved a CdTe polycrystalline thin-film solar cell demonstrating an NREL-confirmed, total-area efficiency of 16.5% by using new materials and the modified device structure. To apply the high-efficiency CdTe cell fabrication technique, we developed two manufacturing processes for producing high-efficiency CdTe modules with the potential of high throughput and low cost. 相似文献
17.
Yu-Hong LinPo-Ching Yang Jing-Shun HuangGuo-Dong Huang Ing-Jye WangWen-Hao Wu Ming-Yi LinWei-Fang Su Ching-Fuh Lin 《Solar Energy Materials & Solar Cells》2011,95(8):2511-2515
The selection of carrier transporting layer in polymer solar cells is an important issue because the nature and direction of carrier transport can be manipulated by inserting different functional layers in the device structure. In this work, we report a very efficient inverted polymer solar cell (PSC) system based on regioregular poly(3-hexylthiophene) and a n-type acceptor, bis-indene[C60]. With a pair of metal oxides and the insertion of TiO2 nanorods electron collecting layer between the ZnO thin film and the active layer, the device efficiency can be greatly improved. The contact area between the active layer and the electron collecting layer, as well as the thickness of active layer, can be increased with the incorporation of TiO2 nanorods. As a result, photocurrent can be enhanced due to more absorption of light and more charge separation interface. In addition, the larger contact area and the crystalline TiO2 nanorods provide a more efficient transporting route for the carriers to the cathode. The most efficient device demonstrated shows a high power conversion efficiency of 5.6% with the inverted structure. 相似文献
18.
C. H. Huang Sheng S. Li W. N. Shafarman C. -H. Chang E. S. Lambers L. Rieth J. W. Johnson S. Kim B. J. Stanbery T. J. Anderson P. H. Holloway 《Solar Energy Materials & Solar Cells》2001,69(2)
The alternative buffer layer material Inx(OH,S)y was deposited on Cu(In,Ga)Se2 (CIGS) thin films by chemical-bath-deposition (CBD). The impurities in Inx(OH,S)y buffer layers and their atomic concentration were characterized by X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) analyses. In addition, AES was used to depth profile the samples. The band-gap energy of the deposited Inx(OH,S)y was determined from optical absorption data. Both the dark- and photo-current-voltage (I–V) characteristics of the CIGS solar cells with Inx(OH,S)y buffer layers were measured, and the results were compared to the CIGS cells deposited with CBD CdS buffer layers. 相似文献
19.
Satoru Seike Keisuke ShiosakiMasamichi Kuramoto Hironori KomakiKoji Matsubara Hajime ShibataShogo Ishizuka Akimasa YamadaShigeru Niki 《Solar Energy Materials & Solar Cells》2011,95(1):254-256
We have developed a fabrication process for integrated submodules using Cu(In,Ga)Se2 (CIGS) absorbers deposited by in-line three-stage evaporation. An in-situ monitoring system for the compositions and thicknesses of the CIGS absorbers was also developed. High-performance CIGS submodules with efficiencies as high as η=15.8% with 17 interconnected cells (aperture area: 76.5 cm2) have been fabricated. 相似文献