The semiconductor ZnO of large gap of 3,4 eV is of great interest for the technological applications as chemical sensors, UV light emission, optical memories, laser emission, solar cells, etc. These applications depend on the electron structure of material. We adopt the density functional theory (DFT) calculation by using the program Wien2K, within the Generalized Gradient Approximation (GGA) and modified Becke–Johnson (mBJ) for studying the electron behavior of ZnO . The features of the valence band derived from the hybridization of Zn -3d and O -2p states. The electron charge density calculated by these simulation methods indicates a charge transfer between zinc and oxygen inducing a difference in electronegativity between both species ( Zn and O ), responsible to ionic character of bonding in ZnO . The predictions based on the GGA and mBJ calculations are confirmed by the results of the experimental spectroscopic analysis Auger Electron Spectroscopy (AES) and Electron Energy Loss Spectroscopy (EELS).

The semiconductor SnO 2 is an important material to be used in different fields as the monitoring of air pollution, toxic gas and other applications as solar cells, optoelectronic devices, etc. The simulation method such as the generalized gradient approximation (GGA) of SnO 2 is very interesting in determining its lattice parameters with accuracy in comparison with the experimental data. The GGA simulation method and the one established by Becke and Johnson mBJ are useful for predicting the electronic properties related to the charge distribution of SnO 2 compound. The calculated density of states and the charge density are well confirmed owing to the experimental results related to the electron energy loss spectroscopy (EELS) technique, very sensitive to the characterization of materials.