THz transient photoconductivity of the III–V dilute nitride GaP y As1−y−x N x

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 = 3.2 +/- 0.8 x 10(-8) cm(3) s(-1). We discuss the implications for applications in solar energy.