Radiation-induced transformation of radiative exciton complexes bound to nitrogen in GaP : N green light-emitting structures

Abstract

The spectral, kinetic and amplitude characteristics of electroluminescence in GaP : N-based light-emitting structures irradiated by neutrons (fluences Φ=l0 10–10 13 cm −2) are studied. The formation of nitrogen NN 1 complexes is found to occur due to the association of nitrogen (isoelectronic impurity) atoms, N P, caused by radiation-enhanced diffusion via the non-radiative complexes. This process results in an increase of the emission intensity from the excitons bound to the NN 1 complexes. This is evidenced by the difference between the fluence dependencies of A- and NN 1-exciton emission intensities and that of the minority charge carrier lifetime. These dependencies show that, along with the N P association into N PN P pairs, there occurs also a process of N P generation due to the capture of optically non-active nitrogen atoms by high-mobility radiation-induced phosphorus vacancies.