Study of chemically synthesized SHI irradiated CdS nanostructured films

Study Of Chemically Synthesized SHI Irradiated CdS Nanostructured Films

P.K. Mochahari^1*, Ananta Rajbongshi², Nava Choudhury³, F. Singh⁴, K.C. Sarma¹

¹Department of Instrumentation & USIC, Gauhati University, Guwahati 781014, India

²Department of Physics, Gauhati University, Guwahati 781014, India

³Department of Physics, Pub Kamrup College, Baihata Chariali, Kamrup, Assam 781381, India

⁴Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067, India

Adv. Mater. Lett., 2015, 6 (4), pp 354-358

DOI: 10.5185/amlett.2015.5719

Publication Date (Web): Mar 21, 2015

E-mail: mochaharip@rediffmail.com

Full Article

Abstract

Cadmium sulphide (CdS) nanostructured films were prepared by chemical bath deposition (CBD) method at room temperature. The prepared films were subjected to swift heavy ion (SHI) irradiation by using 100 MeV Si⁸⁺ ion beams at various fluences from 1x10¹¹ to 1x10¹³ ions/cm². Structural, morphological, optical properties of the pristine and irradiated films were characterized by X-ray diffractrometer (XRD), high resolution transmission electron microscope (HRTEM), UV-Vis spectroscopy and Raman spectroscopy. XRD study confirms the formation of nanocrystalline cubic phase in all the films. The crystallite size is found to increase from 7nm to 9 nm and shift of peak positions are observed due to irradiation. The lattice strain and dislocation density of the samples are of the order of 10^-3and 10¹⁶ m^-2respectively and the values are found to decrease upon irradiation. HRTEM images show that the shapes of the particles are nearly spherical and the selected area electron diffraction (SAED) pattern of HRTEM have also supported the formation of cubic phase CdS. The optical absorption spectra exhibit shift in the fundamental absorption edge and the optical band gap decreases from 2.585eV to 2.513 upon SHI irradiation. Three intense Raman lines for pristine as well as irradiated CdS have been observed and all the samples show shift in Raman lines relative to bulk CdS due to phonon localization. The SHI irradiation on chemically deposited CdS films is an important tool used for modification of structural, morphological and optical properties of the films for possible applications in device fabrication.