GaPN dilute nitride fabricated by ion-implantation and pulsed laser melting

It is challenging to achieve luminescence from GaP due to its indirect bandgap. This restricts the application of GaP for photonic devices.
In this contribution we present the broad-band luminescence from a multi-energy-level structure based on GaP. Such optically active layer is performed by nitrogen-implantation into commercial (100) GaP wafers followed by nanosecond-range pulsed laser melting. The microstructural and optical properties of the fabricated GaPN/GaP samples were investigated by means of X-ray diffraction (XRD), micro-Raman spectroscopy, photoluminescence (PL) and photoreflectance (PR) spectroscopy. The XRD results indicate that the pulsed laser treatment leads to the recrystallization of the implantation-induced amorphous layer and the incorporation of nitrogen into the GaP lattice. The PL spectra confirm directly the formation of optically active diluted nitride layer. Moreover, the obtained multi-band PL and micro-Raman spectra suggest a local enrichment of nitrogen in the implanted layer, i.e., the formation of GaN/GaN1-xPx crystallites, which are embedded in a porous GaP1-yNy/GaP layer. Such system exhibits a wide range of strong luminescence and absorption from 380 nm to 700 nm. The structure has promising prospects in photovoltaic and white-light-emitting applications.