Photovoltaic properties of n-CdS1−xTex thin film/polysulphide photoelectrochemical solar cells prepared by chemical bath deposition
Introduction
Photovoltaic has emerged as a fast developing field due to the global search for alternative sources for power generation. Ever-abundant solar energy can be harnessed by suitable devices called photovoltaic cells or solar cells for low-cost conversion of solar radiations into electrical energy. Thin film based photoelectrochemical solar cells have wide applications due to their low fabrication cost, high-throughput processing techniques and ease of junction formation with an electrolyte. Among the materials that have attracted attention in thin-film polycrystalline form are II–VI and I–III–VI2 ternaries and multiternaries. These semiconductor materials are attractive especially in thin film solar cell application, because of their high optical absorption (≥104 cm−1) and their versatile optical and electrical properties. These electrical and optical properties can suitably be tailored and tuned to the specific need in a given device structure. Among the Cd-chalcogenide group, the most prominent is the Cd–S–Te ternary alloy, the band gap of which can be tailored close to the solar-energy maximum (≅1.4 eV) [1], [2], [3], [4], [5]. In this context, a ternary chalcogenide, especially CdS1−xTex has an added advantage of tailoring the band gap to cope with the visible spectrum [6], [7], [8], [9]. We, therefore, planned and propose through these investigations to synthesize CdS1−xTex thin composite layers of variable composition and to use them in photoelectrochemical application. The electrochemical performance of the cells deviced out of these electrodes has been examined as a function of the electrode composition and correlated with the various materials properties.
Section snippets
Preparation of CdS1−x Tex electrodes
CdS1−xTex (0≤x≤1) thin film electrodes of varying composition were obtained onto the good quality-mirror grade polished stainless steel substrates. Cadmium sulphate, thiourea and sodium tellurosulfate were used as the source materials. For deposition, 10 ml, 1 M cadmium sulphate was complexed with a triethanolamine agent. To this, sodium hydroxide and ammonia were added to adjust the pH of the reaction mixture (pH 10). Thiourea (0.33 M) and sodium tellurosulphate (0.33 M) in appropriate
Results and discussion
The characteristic features of a semiconductor and an electrolyte redox systems can be coupled together in the form of an electrode/electrolyte interface, the properties of which can give a good deal of information regarding the charge transfer mechanism both in dark and in light across an electrode/electrolyte interface. An easy method of fabricating a semiconductor/electrolyte interface is to immerse a semiconductor electrode directly into an electrolyte couple. Upon immersion, charge
Conclusions
The results suggest that the addition of only a small amount of CdTe improves significantly the maximum conversion efficiency of a CdS photoelectrode. The performance is found to be optimal at x=0.1 and is ascribed mainly to the increased flat band potential, decreased band gap, increased photoelectrode absorption and improved grain structure.
References (13)
- et al.
Solid State Commun.
(1996) J. Appl. Phys.
(1956)- et al.
J. Electrochem. Soc.
(1984) - et al.
J. Electrochem. Soc.
(1980) - et al.
Nature (London)
(1976) - et al.
J. Appl. Phys.
(1985)
Cited by (15)
Tunable emission and conductivity enhancement by tellurium doping in CdS nanowires for optoelectronic applications
2017, Physica E: Low-Dimensional Systems and NanostructuresCitation Excerpt :A large number of reports are available on the CdS nanostructures doped with transition metals/post-transition metals other than Te. A few reports are available on Te doped thin films/quantum dots [35–40]. However, no study is available on Te doped in 1D CdS nanostructures.
Effect of complexing agent on the photoelectrochemical properties of bath deposited CdS thin films
2010, Applied Surface SciencePulse plated CdS<inf>x</inf>Te<inf>1-x</inf> films and their properties
2009, Solar EnergyTiO<inf>2</inf> nanotubes and its composites: Photocatalytic and other photo-driven applications
2013, Journal of Materials ResearchMorphological and optical properties of mixed cadmium cobalt selenide thin film synthesized by chemical bath deposition method for photoelectrochemical applications
2016, Journal of Materials Science: Materials in ElectronicsA review on thin films on indium tin oxide coated glass substrate
2016, Asian Journal of Chemistry