Abstract
In this research we study the effect of Annealing and doping by 10% Cupper on some optical properties of (ZnS) thin films (energy gap, absorption coefficient , extinction coefficient) as a function of photon energy .The optical properties were studied through Visible and Ultra-volit wavelength range (300-900nm) using UV-visible spectrometer, these properties were studied before and after annealing and doping . It is found that the energy gap was (3.6eV) before annealing and doping but after annealing and doping it is found (3.7eV, 3.4eV) respectively. Absorption and extinction coefficient increased after annealing and decreased after doping .