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Abstract. PbSe thin films have been deposited on microscope glass substrates by chemical bath deposition technique. The chemical bath consisted of lead nitrate, sodium selenate and triethanolamine solutions. The influence of bath temperature on the properties of PbSe films was investigated. The X-ray diffraction, atomic force microscope and UV/Vis Spectrophotometer were used to obtain the structural characterization, surface morphological and absorbance data, respectively. Based on the X-ray diffraction results, the thin films obtained were found to be polycrystalline in nature with cubic structure. The intensity of the (111) peak showed a significant increased as the bath temperature was increased from 40 to 80°C. The films deposited at 80°C indicated that the crystallinity was improved and more PbSe peaks were observed. On the other hand, the grain size, film thickness and surface roughness were increased while band gap energy decreased as could be observed in atomic force microscope and UV-Vis optical studies, respectively.
Keywords: Lead selenide; X-ray diffraction; Optical properties; Chemical bath deposition; Thin films.
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INTRODUCTION
Lead selenide is an important semiconductor material with interesting properties such as direct band gap and abundance in nature. Thus, lead selenide thin films have been widely used in a variety of fields such as solar cells, thermoelectric cooling, optical recording, light emitting diodes, sensors, laser and thin film transistors. Several techniques have been applied to obtain lead selenide thin films such as electrodeposition [1], chemical bath deposition [2], electrochemical atomic layer epitaxy [3], photochemical [4], molecular beam epitaxy [5], pulsed laser deposition method [6] and vacuum evaporation [7]. Basically, thin films prepared by chemical methods such as chemical bath deposition method and electrodeposition method are generally less expensive than those prepared by the capital-intensive physical technique. The chemical bath deposition method is an electroless method that is attractive as a simple, low cost instrumentation and potential for large-scale production. Up-to-date, chemical bath deposition method has been successfully used to deposit various thin films including NiSe [8], PbS [9], CdTe [10], AgIn^sub 5^S^sub 8^ [11] and Cu^sub 4^SnS^sub 4^ [12].
The present work reports the preparation and physical characterization of PbSe thin films onto microscope glass substrates using chemical bath deposition method. The chemical bath contains lead nitrate and sodium selenate which provides...