Microstructural and optical properties of ferromagnetic (Ga,Mn)N semiconductor

Abstract

N and Mn ions were co-implanted into p-type GaN and subsequently annealed at 700 - 900 degreesC. Compared with the Mn-implanted sample, the (Mn+N)-implanted sample revealed a larger ferromagnetic signal. The intensity of the Mn-related photoluminescence peak increased as N ions were implanted, indicating an increase in hole concentration due to an enhanced activation of Mn impurities in p-type GaN. From Raman spectra, a compressive stress was induced in the (Mn+N)implanted GaN, meaning that the concentration of Mn ions that occupied Ga sites increased, resulting in the reduction of Mn-N compounds such as Mn6N2.58. As a result, the N-vacancies reduced and net hole concentration increased, leading to the enhancement of the ferromagnetic property.