Influence of metalloid elements (Ge, As and In) on the electronic and optical properties of GaN semiconductor: A first-principles investigation

GaN is recognized as the fascinating third generation semiconductor material because of the wide band gap, good electronic mobility and high breakdown electric field. However, the improvement of electronic and optical properties is very significance so as to meet the demand of the future optoelectronic devices. To improve the electronic and optical properties of GaN semiconductor, the effect of metalloid elements on the structural stability, electronic and optical properties of the hexagonal GaN is studied by the first-principles calculations. Similar to the semiconductor feature of Ga, three doped metalloid elements: Ge, As and In are considered. The calculated result shows that three TM-doped GaN are thermodynamic stability. In particular, the Ge-doped GaN has excellent thermodynamic stability compared with the As-doped and In-doped GaN. Importantly, it is found that the Ge-doping GaN shows metallic behavior. Furthermore, the calculated band gap of the As-doped and Indoped GaN is smaller than that of the band gap of GaN. Naturally, these doped metalloid elements are beneficial to the electronic mobility and electronic transport capacity for GaN semiconductor. In addition, the In-doping induces the first peak to red shift from the ultraviolet region to the visible light. Therefore, I believe that these metalloid elements can improve the electronic and optical properties of GaN semiconductor.