  THz Time-Resolved Photoconductivity is used to probe carrier dynamics in the
dilute III-V nitride GaP0.49As0.47N0.036. In these measurements a femtosecond
optical pump-pulse excites electron-hole pairs, and a delayed THz pulse
measures the change in conductivity. We find the photoconductivity is dominated
by localized carriers. The decay of photoconductivity after excitation is
consistent with bimolecular electron-hole recombination with recombination
constant r = 3.2E-8 +/-0.8E-8 cm3/s. We discuss the implications for
applications in solar energy.
