^aLaboratory of Research on Physico-Chemistry of Surface and Interface

(LRPCSI), University of 20 August 1955 Skikda, BP 26, Road El Hadaiek, Skikda, 21000, Algeria

^bLaboratory of Mechanical and Materials Engineering (LGMM), University of 20 August 1955 Skikda, BP 26, Road El Hadaiek, Skikda, 21000, Algeria

^cIonized Media & Laser Division (IMLD), Center for Development of Advanced

Technologies (CDTA), Cité 20 Août 1956, Baba Hassen, Algiers, 16081, Algeria dDepartment of Industrial Engineering, Faculty of Technology, University Batna 2 Chahid Mostefa Ben Boulaid, Rue Chahid Boukhlouf M. El Hadi, Batna, 05001,

Algeria

^eMicro-manufacturing Technology Platform, Center for Development of Advanced Technologies (CDTA), Cité 20 Août 1956, Baba Hassen, Algiers, 16081, Algeria fDepartment of Material Sciences, University of Algiers Ben Youssef Ben Khadda, 2 Rue Didouche Mourad, Algiers, 16000, Algeria

^gMicroelectronic & Nanotechnology Division, Center for Development of

Advanced Technologies (CDTA), Cité 20 Août 1956, Baba Hassen, Algiers,

16081, Algeria

Pure zinc oxide (ZnO) thin films, along with manganese (Mn) doped counterparts, were produced using rapid thermal evaporation technique on ordinary glass substrates. Post- annealing treatments resulted in the formation of hexagonal wurtzite structures in the deposited layers. The Raman results unveiled the presence of A1(LO) and LVM vibration modes in each sample that were doped. Interestingly, the undoped sample lacked the LVM mode while showcasing the emergence of LA + TO combined phonons. Employing a novel approach reliant on the Dragonfly Algorithm, optical parameters were extracted, revealing a drop in the bandgap energy of the films from 3.95 eV to 3.79 eV.