ESJ Natural/Life/Medical Sciences www.eujournal.org 186 The Effect of B, Al, N, and P Impurities on the Electronic Structure of Si 0.3 Sn0.7 Ge alloy: A First-Principles Approach Collins E. Ouserigha, (Ph.D.) Ayibapreye K. Benjamin, (Ph.D.) Niger Delta University, Nigeria Doi:10.19044/esj.2022.v18n3p186 Submitted: 04 October 2021 Accepted: 26 December 2021 Published: 31 January 2022 Copyright 2022 Author(s) Under Creative Commons BY-NC-ND 4.0 OPEN ACCESS Cite As: Ouserigha E.C. & Benjamin A.K. (2022). The effect of B, Al, N, and P impurities on the electronic structure of Si 0.3 Sn 0.7 Ge alloy: a first-principles approach. European Scientific Journal, ESJ, 18 (3), 1. https://doi.org/10.19044/esj.2022.v18n3p186 Abstract This study examines the effect of doping Si 0.3 Sn0.7 Ge with an impurity element X (B, Al, N, or P) on the Sn site, using first-principle calculations based on the fully self-consistent Korringa-Kohn-Rostoker method with the coherent potential approximation (KKR-CPA). To treat several forms of chemical disorders of Si 0.3 Sn0.7 Ge, X-doping was carried out by substituting small amounts of Sn with each element X, which gives rise to the alloy Si 0.3 Sn 0.7-yXyGe. As the X content increases from y = 0.01 to 0.06, the Fermi level maintains its position in the conduction band edge. While the number of states at the Fermi level decreases. With 1% X impurity added to the alloy Si 0.3 Sn 0.7-yXyGe, the number of carriers (electron and hole) states was generally enhanced. For the case of X = P, when compared to the parent material Si 0.3 Sn0.7 Ge, an enhancement of 0.04 states/eV was observed. Due to the increase in the number of states, which indicates an improvement in thermopower, these alloys Si 0.3 Sn0.7-yXyGe are promising for application as n-type electrodes in a thermoelectric generator (TEG). Keywords: First-principles, chemical disorders, thermopower, thermoelectric generator, KKR-CPA.