Mass Transfer Study on Improved Chemistry for Electrodeposition of Copper Indium Gallium Selenide (CIGS) Compound for Photovoltaics Applications

Abstract

Copper indium gallium selenium (CIGS) films are attractive for photovoltaic applications due to their high optical absorption coefficient. The generation of CIGS films by electrodeposition is particularly appealing due to the relatively low capital cost and high throughput. Numerous publications address the electrodeposition of CIGS; however, very few recognize the critical significance of transport in affecting the composition and properties of the compound. This study introduces a new electrolyte composition, which is far more dilute than systems that had been previously described, which yields much improved CIGS films. The electrodeposition experiments were carried out on a rotating disk electrode, which provides quantitative control of the transport rates. Experiments with the conventional electrolyte, ten times more concentrated than the new electrolyte proposed here, yielded powdery and non-adherent deposit. By contrast, the new, low concentration electrolyte produced in the preferred potential interval of −0.64 ≤ E ≤ −0.76 V vs. NHE, a smooth and adherent uniform deposit with the desired composition across a broad range of rotation speeds. The effects of mass transport on the deposit are discussed. Sample polarization curves at different electrode rotation rates, obtained in deposition experiments from the high and the low concentration electrolytes, are critically compared. Characterization of the overall efficiency, quantum efficiency, open circuit voltage, short circuit current, dark current, band gap, and the fill factor are reported.

Cu(InGa)(SeS)2 Electrodeposition from a Single Bath Using Pulsing Current Technique

“…In this work, an improved electrolyte is used that allows for the direct electrodeposition of CIGSS from a single bath with a pulsing current technique. Comparing the electrolyte to typical baths reported in the literature, it is noticeably more diluted and similar to the previous work [6][7]. This is a significant study published that was able to achieve the desired composition of CIGSS from a single process chemistry without the addition of any components from the vapor phase.…”

“…The agitation effects were described and the plating conditions were optimized using polarization tests at three rotation speeds (100, 300, and 500 rpm) as in previous work [6][7].…”

“…A hybrid thermal treatment procedure that involves elements addition from the vapor phase as a second step. [3][4][5][6][7]. The chemistry of the electrodeposition bath and the development mechanisms of the CIGSS absorber layer have been studied by several research teams [7][8][9][10].…”

State-of-the-Art Technologies for Building-Integrated Photovoltaic Systems

“…Therefore, this integration can be considered as an optimal function. In addition, metal roofing refers to lightweight metal roofing, with a supplementary layer of PV thin film, typically composed of copper indium gallium selenide (CIGS) photovoltaic cells [126,127]. The flexible lightweight modules that are lightweight BIPV systems, such as rolls and membranes, can be positioned on various surfaces by simple sticking onto the surface without any mounting elements [128].…”

Advances in Nanomaterials for Photovoltaic Applications

“…Besides, as the authors present, these materials are ecologically-friendly, abundant on earth and they could be successfully employed not only in solar energy photo-conversion devices, but in other applications to generate “clean” energy, such as photocatalysis or thermoelectricity. Very good performances of the second generation’ solar cells based on copper indium gallium selenide (CIGS) thin films exclusively grown by electrochemical pathways are also demonstrated elsewhere [ 2 ], as well as the work on ultra-thin noncrystalline cadmium telluride (CdTe) films prepared by the novel blade coating technique that promises to offer a reliable solution for low-cost and large-scale fabrication of solar cells based on semiconducting nanocrystals [ 3 ]. Not in the least, good results were also obtained while testing other main absorber materials for PV cells like antimony selenoiodide (SbSeI) thin films [ 4 ], or by implementing specific innovative fabrication technologies such as engagement of aluminium arsenide (AlAs) capping layers onto indium arsenide/galium arsenide (InAs/GaAs) quantum dot (QD) structures for solar cells [ 5 ].…”