Electrical properties of homogeneous Cu(In,Ga)S2 films with varied gallium content

Kaigawa, R.; Ohyama, Atsuro; Wada, Takahiro; Klenk, R.

doi:10.1016/j.tsf.2006.12.101

Cited by 17 publications

(5 citation statements)

References 8 publications

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“…The cell structure and cross-sectional scanning electron microscopy (SEM) photographs of typical CIGS/Mo structure fabricated on Mo-coated soda-lime glass substrate are shown in Figure 1(a). SEM images show a reduction in grain size with increasing Ga content from top to bottom of absorber layer, which agrees well with the results by other groups [17]. In Figure 1(b), the J-V curve from simulation is compared with experimental data, and inset shows the bandgap grading (Ga content) in absorber layer.…”

Section: Resultssupporting

confidence: 89%

Device Modeling of the Performance of Cu(In,Ga)Se₂Solar Cells with V-Shaped Bandgap Profiles

Kuo

Hsieh

et al. 2014

International Journal of Photoenergy

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The effect of Cu(In,Ga)Se2(CIGS) with V-shaped bandgap on device performance is investigated in detail. A series of Ga/(In+Ga) ratio are set to study the influence of V-shaped bandgap profile on the electricity of CIGS thin film solar cells. The modeling of device current density-voltage (J-V) curve and bandgap grading profile corresponded well to measurement results. Detailed characteristic and modeling results show that an increased gradient of bandgap from valley to the buffer layer CdS will result in a barrier and lead to an enhanced recombination in the valley. This phenomenon can be modified by the back electric field resulting from a gradient bandgap from valley (bandgap minimum) to the Mo back contact. These results indicate CIGS-based solar cells can achieve higher performance by optimizing the V-shaped bandgap profile.

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Section: Resultssupporting

confidence: 89%

Device Modeling of the Performance of Cu(In,Ga)Se₂Solar Cells with V-Shaped Bandgap Profiles

Kuo

Hsieh

et al. 2014

International Journal of Photoenergy

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“…The EQE spectrum of the Ga:CIS_600-based cell showed appreciable blue-shift of the onset wavelength due to the enlargement of E g by the partial replacement of In with Ga: the CIS-based cell showed the EQE onset at 860 nm, which corresponded to the reported E g value of CIS (1.48 eV), 1,2 whereas the Ga:CIS_600-based cell gave the 780 nm onset corresponding to 1.68 of E g . Since E g of the pure Ga analogue (i.e., CuGaS 2 ) is known to be 2.43 eV, 28 the E g value of Ga:CIS with 20% Ga content along with that of In can be estimated to be 1.69 eV when a linear increase of E g with the Ga content in Ga:CIS from zero (CIS) to 100% (CuGaS 2 ) is assumed. The value also coincides well with the E g value of the present Ga:CIS_600 film.…”

Section: Paper Catalysis Science and Technologymentioning

confidence: 99%

Fabrication of CuInS2 and Cu(In,Ga)S2 thin films by a facile spray pyrolysis and their photovoltaic and photoelectrochemical properties

Ikeda

Nonogaki

Septina

et al. 2013

Catal. Sci. Technol.

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“…Meanwhile, they mentioned that the crystalline size decreased with the increase of Ga concentrations, due to the replacement of In 3+ by Ga 3+ ions in CuInS 2 (CIS) crystal lattice. R. Kaigawa etc 33 reported that the grain size decreased with the increasement of Ga content in films. As in our results, the increasing indium content with sintering temperature is also responsible for the enlargement of grain size.…”

Section: Resultsmentioning

confidence: 97%

Preparation of Cu(In,Ga)S₂Absorber Layers for Thin Film Solar Cell by Annealing of Electrodeposited Cu-Ga-S Precursor Layers

Yang

Niu

Wang

et al. 2014

J. Electrochem. Soc.

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Cu(In,Ga)S 2 (CIGS) thin film was synthesized on ITO glass substrate via electrodeposition of Cu-Ga-S precursor layer followed by thermal annealing treatment. Our results show that annealing temperature played an important role on the formation of CIGS crystallites. The pure quaternary chalcopyrite CIGS crystal phase in good crystallization with an uniform and compact surface morphology was reproducibly achieved after sintering at 400 • C. The metallic In atom diffused from the ITO substrate was found to incorporate to the Cu-Ga-S precursor film and allow the conversion of the quaternary chalcopyrite structure. Several characterization methods including X-ray diffraction (XRD), scanning electron microscope (SEM), energy diffraction spectrum (EDS) and highresolution transmission electron microscopy (HRTEM) certified the incorporation of In. A possible growth mechanism for explaining the formation of CIGS thin films is proposed and briefly discussed. Completed CIGS solar cell device achieved a 5.75% total area power conversion efficiency under a simulated AM 1.5 illumination.The development of low-cost efficient solar cells is one of the ultimate solutions for the renewable and clean energy challenge. Chalcopyrite based solar cells are promising candidates for next generation photovoltaic modules due to their high power conversion efficiency, direct bandgap, high absorption coefficient, low toxicity and excellent stability. 1 Up to now, CuInGaSe 2 absorber layer based solar cells have obtained the highest power conversion efficiency of 20.1% in laboratory among the thin film technology. 2 However, it is approaching the theoretical limit. 3 For a further promotion on conversion efficiency, tandem solar cell structures are currently subject of intensive research. 4 For a double solar cell two-terminal tandem system, it has been estimated that the theoretical efficiency exceeds 30%, which is higher than that for single-junction cells. The optimum bandgap for the top cell is in the range of 1.6 to 2.0 eV. 5 Cu(In,Ga)S 2 solid solutions possesses a bandgap from 1.5 eV to 2.43 eV covers the above mentioned range of the optimum bandgap for the top cell. 6 The incorporation of gallium in CIS leading to a quaternary Cu(In,Ga)S2 (CIGS) structure also bears perspectives of a increasing efficiency due to the enlargement of the bandgap energy (E g ) and correspondingly the open-circuit voltage (V OC ) 7-9 comparing to CIS. Though CIS-based solar cell have a strong potential of achieving high efficiency due to its almost ideal bandgap energy of 1.5 eV, 10,11 debates have been going on regarding the limited efficiency and open circuit voltages of the cells remained below the predicted theoretical values. Significant improvement could not be achieved and open circuit voltage values did not typically exceed 730 mV. A further increase in the efficiency is expected from doping or alloying of the CIS absorber material with isovalent and/or non-isovalent substitutional elements. Promising results have been obtained using silver as dopa...

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Electrical properties of homogeneous Cu(In,Ga)S2 films with varied gallium content

Cited by 17 publications

References 8 publications

Device Modeling of the Performance of Cu(In,Ga)Se₂Solar Cells with V-Shaped Bandgap Profiles

Device Modeling of the Performance of Cu(In,Ga)Se₂Solar Cells with V-Shaped Bandgap Profiles

Fabrication of CuInS2 and Cu(In,Ga)S2 thin films by a facile spray pyrolysis and their photovoltaic and photoelectrochemical properties

Preparation of Cu(In,Ga)S₂Absorber Layers for Thin Film Solar Cell by Annealing of Electrodeposited Cu-Ga-S Precursor Layers

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Electrical properties of homogeneous Cu(In,Ga)S2 films with varied gallium content

Cited by 17 publications

References 8 publications

Device Modeling of the Performance of Cu(In,Ga)Se2Solar Cells with V-Shaped Bandgap Profiles

Device Modeling of the Performance of Cu(In,Ga)Se2Solar Cells with V-Shaped Bandgap Profiles

Fabrication of CuInS2 and Cu(In,Ga)S2 thin films by a facile spray pyrolysis and their photovoltaic and photoelectrochemical properties

Preparation of Cu(In,Ga)S2Absorber Layers for Thin Film Solar Cell by Annealing of Electrodeposited Cu-Ga-S Precursor Layers

Contact Info

Product

Resources

About

Device Modeling of the Performance of Cu(In,Ga)Se₂Solar Cells with V-Shaped Bandgap Profiles

Device Modeling of the Performance of Cu(In,Ga)Se₂Solar Cells with V-Shaped Bandgap Profiles

Preparation of Cu(In,Ga)S₂Absorber Layers for Thin Film Solar Cell by Annealing of Electrodeposited Cu-Ga-S Precursor Layers