Structural properties of a GaNxP1-x alloy: Raman studies

Raman measurements in backscattering configuration are employed to characte rize the effect of nitrogen on the structural properties of a GaNxP1-x allo y with x less than or equal to3 %. The following effects of N incorporation on the vibrational spectra of GaNP are observed. First, frequencies of GaP -like and GaN-like longitudinal optical phonons exhibit strong compositiona l dependence, due to a combined effect of alloying and biaxial strain. Seco nd, a dramatic quenching of two-phonon Raman scattering and an emergence of zone-edge GaP-like vibrations are observed. These effects are tentatively attributed to a local distortion of the GaNP lattice and/or compositional d isorder in the alloy. (C) 2001 American Institute of Physics.