Electrodeposition of CuGaSe2 and CuGaS2 thin films for photovoltaic applications

The final publication is available at Springer via http://dx.doi.org/10.1007/s10008-016-3237-0.Abstract CuGaSe2 and CuGaS2 polycrystalline thin film absorbers were prepared by one-step electrodeposition from an aqueous electrolyte containing CuCl2, GaCl3 and H2SeO3. The pH of the solution was adjusted to 2.3 by adding HCl and KOH. Annealing improved crystallinity of CuGaSe2 and further annealing in sulphur atmosphere was required to obtain CuGaS2 layers. The morphology, topography, chemical composition and crystal structure of the deposited thin films were analysed by scanning electron microscopy, atomic force microscopy, energy dispersive spectroscopy and X-ray diffraction, respectively. X-Ray diffraction showed that the asdeposited CuGaSe2 film exhibited poor crystallinity, but which improved dramatically when the layers were annealed in forming gas atmosphere for 40 min. Subsequent sulphurization of CuGaSe2 films was performed at 400 °C for 10 min in presence of molecular sulphur and under forming gas atmosphere. The effect of sulphurization was the conversion of CuGaSe2 into CuGaS2. The formation of CuGaS2 thin films was evidenced by the shift observed in the X-ray diffraction pattern and by the blue shift of the optical bandgap. The bandgap of CuGaSe2 was found to be 1.66 eV, while for CuGaS2 it raised up to 2.2 eV. A broad intermediate absorption band associated to Cr and centred at 1.63 eV was observed in Cr-doped CuGaS2 films.This work was supported by Ministerio de Economia y Competitividad (ENE2013-46624-C4-4-R) and Generalitat Valenciana (Prometeus 2014/044). One of the authors (S. Ullah) acknowledges the European Union (IDEAS-Call-3, Innovation and Design for Euro-Asian scholars) for its financial support.Ullah, S.; Mollar García, MA.; Marí, B. (2016). Electrodeposition of CuGaSe2 and CuGaS2 thin films for photovoltaic applications. Journal of Solid State Electrochemistry. 20(8):2251-2257. https://doi.org/10.1007/s10008-016-3237-0S22512257208Calixto ME, Sebastian PJ, Bhattacharya RN, Noufi (1999) Sol Energ Mat Sol C 59:75–84Mandati S, Sarada BV, Dey SR, Joshi SV (2015) J Power Sources 273:149–157Jacobsson TJ, Fjällström V, Edoff M, Edvinsson T (2015) Sol Energ Mat Sol C 134:185–193Carrete A, Placidi M, Shavel A, Pérez Rodríguez A, Cabot A (2015) Phys Stat Sol (a) 212:67–71Saji VS, Ik-Ho C, Lee CW (2011) Sol Energy 86:2666–2678Park MG, Ahn SJ, Yun JH, Gwak J, Cho A, Ahn SK, Shin K, Nam D, Cheong H, Yoon K (2012) J Alloy Compd 513:68–74Saji VS, Lee SM, Lee CW (2011) J Korean Electrochem Soc 14:61–70Donglin X, Jangzhuang L, Man X, Xiujian Z (2008) J Non-Cryst Solids 354:1447–1450Araujo J, Ortíz R, López-Rivera A, Ortega JM, Montilla M, Alarcón D (2007) J Solid State Electroch 11(Issue 3):407–412Palacios P, Sanchez K, Conesa JC, Fernandez JJ, Wahnon P (2007) Phys Stat Sol A 203:1395–1401Palacios P, Sanchez K, Conesa JC, Wahnon P (2006) Thin Solid Films 515:6280–6284Lee H, Lee J-H, Hwang Y-H, Kim Y (2014) Curr Appl Phys 14:18–22Kim D, Kwon Y, Lee D, Yoon S, Lee S, Yoo B (2015) J Electrochem Soc 162:D36–D41Hou WW, Bob B, Li S, Yang Y (2009) Thin Solid Films 517:6853–6856Lee J, Lee W, Shrestha NK, Lee DY, Lim I, Kang SH, Nah YC, Lee SH, Yi W, Han SH (2014) Mater Chem Phys 144:49–54Yang JY, Lee D, Huh K, Jung SJ, Lee JW, Lee HC, Baek DH, Kim BJ, Kim D, Nam J, Kim GY, Jo W (2015) RSC Adv 5:40719–407257Sall T, Nafidi A, Marí B, Mollar M, Hartiti B, Fahoume M (2014) J Semicond 35:0630021–0630025Lee JH, Song WC, Yi JS, Joonyang K, Han WD, Hawang J (2003) Thin Solid Films 431-432:349–353Prabukanthan P, Dhanasekaran R (2007) Cryst Growth Des 7:618–623Guillemoles JF, Cowache P, Lusson A, Fezzaa K, Boisivon F, Vedel J, Lincot D (1996) J Appl Phys 79:7293–7302Aguilera I, Palacios P, Wahon P (2010) Sol Energ Mat Sol C 94:1903–1906Palacios P, Aguilera I, Wahnón P, Conesa JC (2008) J Phys Chem C 112:9525–952

Interface Defects in CIGS-Based Solar Cells From Coupled Electrical and Chemical Points of View

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ELECTRIC AND CHEMICAL CHARACTERIZATIONS OF THE HETEROINTERFACES IN THE Cu (In, Ga) Se2 SOLAR CELLS

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Ammonia pretreatment influence on the defect properties of Cu (In, Ga) Se/sub 2/solar cells from admittance spectroscopy

International audienceIn thin film polycrystalline CdS/CIGS heterojunction solar cells, understanding the intrinsic and interface defect properties is crucial to optimize their performances. In this paper, we focus our attention on the CdS/CIGS hetero-interface at different stages of its formation. All investigations were carried out on CIGS co-evaporated samples elaborated in pilot-line conditions onto which the CdS layer was deposited by chemical bath deposition (CBD). This latter chemical process involves the use of a NH, solution that modifies the ClGS surface composition. In order to separate the respective role of the NH/sub 3/ bath and the CdS layer thickness , we have investigated samples elaborated with several NH/sub 3/ pretreatment time of CIGS surface prior to CdS deposition. Admittance spectroscopy was used to follow the evolution of the hetero-interface defects properties