Structural and optical properties of Mn-doped CdS thin films prepared by ion implantation

We report on structural and optical properties of Mn-doped CdS thin films prepared by 190 keV Mn-ion implantation at different temperatures. Mn-ion implantation in the fluence range of 1x 10¹³-1x10¹⁶ ions/cm² does not lead to the formation of any secondary phase. However, it induces structural disorder, causing a decrease in the optical band gap. This is addressed on the basis of band tailing due to creation of localized energy states and Urbach energy calculations. Mn-doped samples exhibit a new band in their photoluminescence spectra at 2.22 eV, which originates from the d-d ⁴T₁→⁶AT₁ transition of tetrahedrally coordinated Mn²⁺ ions.