Theoretical study on structural stability and optoelectronic properties of metal-adsorbed two-dimensional GaN

Abstract This paper have studied structural stability and optoelectronic properties of two-dimensional GaN adsorbed by Pt, Al, Ag and Au atoms through using first-principles. The results show that it exhibits completely different results when two-dimensional GaN adsorbs Al atom. For Pt, Ag and Au atoms, the most stable adsorption position is TN, while the most stable position for Al atom is H. After adsorbing Pt, Ag and Au, an impurity energy level is formed between CBM and VBM. On the other hand, the Fermi energy level Al-adsorbed two-dimensional GaN passes through the CBM, showing n-type conductivity. Due to the difference in electronegativity between the atoms, Pt and Au obtain charges of 0.01|e| and 0.04|e| from two-dimensional GaN, respectively, while the Al atoms and Ag atoms transfer 0.14|e| and 1.16|e| into two-dimensional GaN, respectively. In addition, when two-dimensional GaN is adsorbed by metal atoms, optical properties can be adjusted and it will become more inclined to absorb short-wavelength light. Compared to the other three metal atoms, the Al-adsorbed two-dimensional GaN is more advantageous in the infrared band.