CdSe thin films: morphological, optoelectronic and photoelectrochemical studies M. L. Gaur • P. P. Hankare • K. M. Garadkar • S. D. Delekar • V. M. Bhuse Received: 17 September 2013 / Accepted: 25 October 2013 Ó Springer Science+Business Media New York 2013 Abstract Polycrystalline cadmium selenide (CdSe) thin films have been synthesized at room temperature by using chemical bath deposition method. The synthesized films were characterized by using X-ray diffraction (XRD), optical absorbance, electrical conductivity, scanning electron micro- scope, energy dispersive X-ray analysis, photoluminescence and photoelectrochemical (PEC) techniques. The film of 0.84 lm thickness, deposited on glass substrate showed uni- form spherical morphology with an optical band gap of 1.99 eV. The XRD analysis confirmed presence of cubic structure. Scanning electron micrograph shows a typical spherical ball like morphology with large surface area, which is useful for absorption of large solar radiation. The conductivity measurements showed n type semiconducting nature of the film. A PEC cell device fabricated using ‘as deposited’ CdSe film as anode showed a stable conversion efficiency of 0.7 %. 1 Introduction The studies on polycrystalline, semiconducting, binary metal chalcogenide materials belonging to II–VI groups has been a rapidly growing area of research due to their ability to convert solar energy into electricity. The cad- mium selenide (CdSe) is one of the promising semicon- ducting material because of its characteristic size- dependent properties, which allow tailoring of the energy band structure and optoelectronic properties [1–3]. CdSe is of special interest because of its direct optical band gap (1.74 eV). A variety of physical and chemical techniques are available for the deposition of CdSe thin films [4, 5]. A chemical bath deposition (CBD) technique has been used for many decades due to its good applicability for producing large-area thin films. A good adherent thin film can be deposited on any substrate by optimizing the various parameters. The characteristics of deposited film are ‘recipe oriented’ therefore, a large number of studies on this tech- nique have been observed. The recipe oriented characteris- tics motivate the studies on applications of cadmium selenide films in diversified fields. The semiconducting crystalline thin films find very promising applications in optoelectron- ics, photonics, transistors, photovoltaic cells and light emitting diodes [6–12]. The metal chalcogenide thin films can be prepared by using various physical and chemical techniques such as solvother- mal [1], spray pyrolysis [13], vacuum evaporation [14], sput- tering [15], electron beam evaporation [16], electro-deposition [17], photoelectrochemical (PEC) [18], successive ionic layer adsorption and reaction (SILAR) [19], photochemical depo- sition [20] and CBD [21, 22]. CBD is simple and economically viable technique for producing good quality films with better stiochiometry, suitable for device application. In the present work, an attempt is made to synthesize polycrystalline CdSe thin films chemically. The films were characterized by X-ray diffraction (XRD), scanning elec- tron microscope (SEM), energy dispersive X-ray analysis (EDS), optical measurement techniques, photolumines- cence (PL) and PEC studies. M. L. Gaur  V. M. Bhuse (&) Thin Film Research Laboratory, Department of Chemistry, Government Rajaram College, Kolhapur 416004, India e-mail: bhuse_chemistry@rediffmail.com; vijaykbhuse13@gmail.com P. P. Hankare  K. M. Garadkar Solid State Research Laboratory, Department of Chemistry, Shivaji University, Kolhapur 416004, India S. D. Delekar Nanoscience Research Laboratory, Department of Chemistry, Shivaji University, Kolhapur 416004, Maharashtra, India 123 J Mater Sci: Mater Electron DOI 10.1007/s10854-013-1572-9