Photoresponses of manganese-doped gallium nitride grown by metalorganic vapor-phase epitaxy

Abstract

The photoresponses of gallium nitride (GaN) doped with manganese (Mn) grown by metalorganic vapor-phase epitaxy were investigated. The transmission spectroscopy obtained from the Mn-doped GaN exhibited three distinct absorption thresholds at approximately 365, 650, and 830 nm, respectively. The below-band-gap absorption peaks were attributed to the fact that the deep Mn-related states mediate the electronic transition between the valence and conduction bands. A below-band-gap spectral response ranging from 400 nm to 1000 nm was also observed from a typical GaN p-i-n photodetector with Mn-doped absorption layer. The significant below-band-gap spectral responses showed that the Mn-doped GaN-based materials have promising applications in intermediate band solar cells.