LUMINESCENCE QUENCHING AND THE FORMATION OF THE GAP1-XNX ALLOY IN GAP WITH INCREASING NITROGEN-CONTENT

A study of the luminescence properties of epitaxial GaP containing atomic N grown by molecular beam epitaxy using NH3 and PH3 as the column V sources was conducted. The 77 K photoluminescence spectra of the N-doped epitaxial GaP showed a continuous redshift, from 5691 angstrom (2.18 eV) to 6600 angstrom (1.88 eV), resulted when the N concentration exceeded approximately 5-7 x 10(19) cm-3. This energy shift was found to be consistent with energy gap predictions using the dielectric theory of electronegativity for the GaP1-xNx system. The data also indicate that the emission intensity was maximum for N approximately 1 x 10(20) cm-3, and then monotonically decreases with increasing N content. This is consistent with the formation of an indirect band-gap semiconductor.