Study of electronic properties by persistent photoconductivity measurement in Ga_xin_1-xN_yAs_1-y grown by MOCVD

Electronic properties of GaInNAs thin films have been investigated by the temperature-dependent Hall-effect and persistent photoconductivity (PPC) measurements. The Ga_xIn_1-xN_yAs_1-y thin films were grown by metal-organic chemical vapor deposition (MOCVD) on GaAs(100) substrates. High resolution X-ray diffraction (HR-XRD) and photoluminescence (PL) were used to determine the crystal quality. Compared with the N-free sample, the mobility of the GaInNAs sample quenched significantly due to the lattice defects induced by the small amount of nitrogen atoms incorporated during growth. The free carrier concentration of the GaInNAs samples was not affected by the increasing temperature ranging from 120 K to 400 K. Persistent photoconductivity (PPC) was also observed in this material, and the properties of PPC were found to depend on the temperature and nitrogen content. The relationship between trend toward saturation of the free carrier concentration of the temperature-dependent Hall measurement and PPC is also discussed.