Structural, electronic and magnetic properties of Ti-doped polar and nonpolar GaN surfaces

Abstract

Based on density functional theory, first-principles calculations were performed in order to study the titanium incorporation on polar and nonpolar GaN surfaces. The formation energy calculations indicate that Ti impurity atoms prefer to incorporate in surface layers (first and second) of GaN. It is also concluded that the incorporation of Ti atoms in Ga-substitutional sites are more energetically favorable compared with N-substitutional or interstitial sites on the polar and nonpolar GaN surfaces. For Tirich growth conditions, formation energy calculations show the formation of TixN layers on the a and c GaN surfaces, which corroborates recent experimental observations. Results also display that the 3d-Ti states are the responsible for the metallization of the surface on the c and m planes, forming an intermetallic alloy (TixN), which could be used as low-resistance ohmic contacts for GaN. In addition, the magnetic properties with Ti doping show magnetization of about 1.0 μB/Ti atom for the nonpolar GaN surfaces.

Investigating structural, electronic, magnetic, and optical properties of Zr doped and Ti-Zr co-doped GaN for optoelectronic applications

“…However, significant contribution of Ti 3d-states has been noticed and is responsible for tuning electronic behavior of Ti@GaN material. Similar spin polarized DOS trends have been reported in the study of Victor Mendoza-Estrada et al[52], Miguel J Espitia R. et al[53] and Zhihua Xiong et al[54]. Density of states shows symmetric distribution for Zr doped GaN during −5 eV to 5 eV, energy range (figure3(c)).…”

Realizing Shallow Acceptor Levels in Delafossite CuAlO2 () Surfaces by Chalcogen Doping

“…However, the theoretical researches of substitution doping on CuAlO 2 surfaces and the enhancement mechanism of p‐type conductivity have not been referred. It is important to study the surface stability and electronic properties of substitution doping on CuAlO 2 surfaces due to that the doping may induce important and interesting phenomena . Therefore, the surface stability and electronic states of chalcogen doping at the delafossite CuAlO 2 () surfaces are investigated using the first‐principles calculations.…”

Impact of Ti Doping on the Microstructure and Mechanical Properties of CoCrFeMoNi High-Entropy Alloy

“…For example, Ti doping in silicon (Si) can lead to an increase in the number of free electrons, which can enhance the electrical conductivity and make Si more suitable for applications such as solar cells and microelectronics [22]. Similarly, Ti doping in gallium nitride (GaN) can enhance the electrical conductivity and improve the performance of GaN-based devices (LEDs) and the mobility of electrons in transistors (HEMTs) [23,24].…”