135 JAPHAC (7): 135-139 Thaís Karine de Lima Rezende 1* , William Oliveira Soté 1 , Eduardo de Faria Franca 1 1- Laboratório de Cristalografia e Química Computacional (LCQC), Institute of Chemistry, Federal University of Uberlândia, MG, Brazil. *Corresponding Author: thaislimaufu@gmail.com ________________________________________________________________________________________________ Abstract: This work describes some doping effects of silver Ag + doped wurtzite zinc oxide (ZnO) using semiempirical quantum chemistry simulation with PM7 Hamiltonian. The electronic and structural properties of a undoped ZnO are compared with its doped form. The undoped ZnO initial structures were used to validate the methodology and in this solid solution some Zn 2+ ions were substituted by Ag + ions to simulate the doping procedure. It was created four doped systems containing 4.71, 14.14, 28.28 and 42.42 wt.% of Ag + ions. The theoretical study showed some tendencies expected by the literature, as the morphology preservation and the increasing of the heat of formation according to the doping advance. The electric dipole distribution also increased and rearranged itself among the whole structure as the amount of Ag + increased. Keywords: nanoparticles; semiempirical; doping. ________________________________________________________________________________________________ INTRODUCTION Zinc oxide (ZnO) has been a major target of metals doping studies due to the enhancement of its natural optical, electronic and structural properties, resulting in several industrial and technological applications, such as piezoelectricity, electronic and photonic applications, ultraviolet semiconductor lasers, solar cells, and others[1]. The hexagonal structure of the zinc oxide belongs to the space group P63mc, with parameters a = b = 3.249 Å, c = 5.207 Å (wurtzite, JCSPD 36-1451) and the 16 angles  =  = 90 ° and  = 120 °. In addition, it has a direct gap of 3.37 eV[1], [2]. Semiconductor materials, such as ZnO, being intermediate to insulators and conductors, are malleable with respect to the manipulation of electrical conductivity properties. One way to modify these properties is through the doping. This can be done by replacing the metal (intrinsic doping) or by incorporating it into the crystalline lattice (extrinsic doping), depending on characteristics such as ionic radii proximity, reaction medium, structure tension and others[2]. In this present work, the chosen dopant was the ion Ag + . When incorporated in the ZnO host lattice, Ag + is considered a n-type dopant because it has more electrons in its valence layer when compared to Zn 2+ , thus increasing the negative charge of the conduction band in relation to the holes present in the valence band [1], [3]. The Ag + can contributes to the increase in the conductivity of the material, increase of the electric dipole, and shifts the infrared absorption region[3]. Much effort has been made to produce and improve materials such as ZnO. On the other hand, theoretical approaches are also important in order to predict changes in electronic, optical, and structural properties. The synthesis of materials can often be expensive and require several tests. Previous theoretical studies allow to understand properties that are not so easily accessible at the experimental level. Thus, using computational SEMIEMPIRICAL STUDY OF DOPING EFFECTS IN SILVER Ag + DOPED WURTZITE ZINC OXIDE (ZnO) Submitted in: 17/01/2021 Corrected Version: 28/01/2021 Accepted: 22/02/2021 ISSN 2358-3495 japhac.wix.com/japhac Original Article