International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395 -0056
Volume: 04 Issue: 01 | Jan -2017
p-ISSN: 2395-0072
www.irjet.net
Compositional, structural and optical properties analysis of β-In2S3 Thin Films Prepared by Chemical Spray Pyrolysis and Electrochemical Deposition Techniques D. Soro1,2, B. Fofana1,M. Sidibé3, B. Aka4, B. Mari2, S.Touré3 1Ecole Normale Superieure (ENS) d’Abidjan, 08 BP 10 Abidjan 08, Côte d’Ivoire Politècnica de Vàlencia, Departament de Física Aplicada-IDF, Camí de Vera s/n, Vàlencia, 46022, Spain 3 Université FHB D’Abidjan-Cocody, Laboratoire d’Energie Solaire, 22 BP 582 Abidjan 22, Côte d’Ivoire 4 Université Nangui Abrogoua, UFR-SFA, 02 BP 801 Abidjan, Côte d’Ivoire
2Universitat
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Abstract – An increased attention is devoted to interfacial
In2S3 thin films because of their potential application as a new generation of buffer layer in copper indium gallium diselenide (CIGS)-based solar cells. In this paper, thin films of β-In2S3 were deposited by Chemical Spray Pyrolysis and Electrochemical deposition onto FTO Coated Glass Substrates. Characterization of the films was carried out by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS). Optical analysis to determine band gap gives band gap varying from 2.45eV to 2.90 eV which are very close to the accepted values. The structural analysis reveals films with (0 0 12) as main peak for all samples in all case. Key words : Indium sulfide, Buffer Layer, electrodeposition ,Spray Pyrolysis, DMSO,FTO.
1.INTRODUCTION Needless to say one of the crucial issues in recent decades has been the increasing energy needs. When facing, as we are to this problem, a transition out of the fossil civilization is necessary. A promissing alternative source of energy is the use of solar cells. Finding viable alternatives also to siliconbased photovoltaics, through low-cost solution processable materials, is important. The international scientific community constantly fosters the development of innovative solar energy transducing devices. In the recent decade a large number of semiconductor materials have been studied for using in solar cells . Most promising materials for the use as light absorbers in thin film solar cells are chalcopyrites type semiconductors such as CIGS. CIGS absorbers need a buffer layer to form photovoltaic heterojunctions. Currently one of the best buffer materials for this purpose is a thin CdS film [1]. However, the use of cadmium in PV devices is undesirable from the view point of environmental safety [2]. Serious efforts have been made to substitute the CdS buffer layer by other non-toxic low-absorbing materials. Indium sulfide (In2S3) thin films as an n-type semiconductor have © 2017, IRJET
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recently attracted considerable attention because of their interesting physical properties, which are suitable for optoelectronic device fabrication. These films have a great potential for photovoltaic applications .In2S3 is one of the possible candidates to replace CdS as buffer layer. This compound can be found under three polymorphic forms. The cubic α uform [3] is stable above 693 K and crystallizes in the defect spine! structure (a = 10.77Ȧ). The stable room temperature phase is β-In2S3 [4]. A third modification (γIn2S3) with trigonal symmetry has been reported above 1047 K [5]. Depending upon the type and composition, the band gap reported for In2S3 compound varies between 2.0 and 2.45 eV [6]. Hetero-junctures as CIGS/ β -In2S3 [7] or CIS/In(OH,S) [8] have been built by CBD with conversion efficiencies of 15.7% and 11.4% respectively. Indium sulfide has elaborated using various techniques like Successive Ionic Layer Adsorption and Reaction (SILAR) [9], Thermal Evaporation (TE) [10], Atomic Layer Deposition (ADL) [11], Chemical Bath Deposition (CBD) [12] etc. It was noted that the quality of films depends strongly on growth technique. Electrodeposition and Chemical Spray Pyrolysis are also interesting for In2S3 synthesis. In the present work, we prepared β-In2S3 by two different ways :Chemical Spray Pyrolysis and Electrochemical deposition. The structure, morphology,optical properties and composition were studied and compared.
2. Experimental procedure 2.1. Preparation of thin films Thin films of β-In2S3 were prepared by Chemical Spray Pyrolysis and Electrochemical deposition onto FTO Coated Glass Substrates. Using Chemical Spray Pyrolysis, Indium sulfide (In2S3) thin films were prepared onto FTO (Fluorine Doped Tin Oxide) coated glass substrate from aqueous solution containing indium (III) chloride (InCl3) (99.999%), thiourea (CS(NH2)2) ISO 9001:2008 Certified Journal
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