Enhanced optical absorption in visible range in Mn doped AlP: A density functional theory study

Since the first fabrication of (In, Mn)As diluted magnetic III-V compound semiconductors reported, much effort has been made to find ferromagnetic semiconductors. Mn-doped zinc-blende AlP has more stable ferromagnetic state than Mn-doped AlN, but has received little attention due to its indirect band-gap. Note that, a direct band-gap in AlP nanotubes or strained-single layer AlP film were demonstrated by theoretical calculations. We therefore investigate the magneto-optical properties of Mn-doped AlP by density functional theory within the generalized approximation + U (GGA + U). After Mn doping, an unexpected optical absorption in the visible range was observed compared with pure AlP. The absorption onset exhibited blue shift at highest Mn concentrations (MnP). The high optical adsorption and bandgap tenability in the visible optical range make Mn-doped AlP highly desirable for magneto-optical and lighting applications.