RAMAN-SCATTERING AND OPTICAL-ABSORPTION STUDIES OF AR-FILMS( IMPLANTED CDS THIN)

The effect of argon ion implantation on chemical bath deposited Cadmiu m sulphide (CdS) thin films is investigated by X-ray diffraction, Rama n scattering and optical absorption techniques, The X-ray diffraction pattern of the As-deposited CdS thin films shows the presence of both sphalerite (cubic) and wurtzite (hexagonal) phases, Phase transition f rom the As-deposited mixed phase to the more stable hexagonal phase al ong with grain growth is observed on post implantation annealing. Opti cal absorption studies of the implanted films reveal a reduction in th e band gap on implantation and its recovery to As-deposited values on post implantation annealing. A decrease in the intensity of the Raman peak of CdS AI(LO) mode is seen on implantation and on post implantati on annealing, the intensity is found to increase. A drastic reduction in the full width at half maximum (FWHM) value of the films subjected to post implantation annealing compared to that of As-deposited or imp lanted films suggests the removal of defects and strain during anneali ng. The peak position of the Raman mode of CdS remains more or less th e same. (C) 1997 Elsevier Science B.V.