Deeper insight into non-equilibrium carrier dynamics in InP:Fe: experimental and modeling

Non-equilibrium carrier generation, transport, and recombination have been investigated in Fe-doped InP crystals experimentally in subnanosecond time domain by using time-resolved picosecond four-wave mixing technique. The carriers were generated by below band-gap excitation at 1064 nm (hv = 1.17 eV), what allowed photoexcitation of non-equilibrium carriers from/via Fe-related deep levels. The contributions of Fe2+/Fe3+ deep level states and of the excited state Fe2+* have been analyzed by numerical modeling, using the relevant model which took into account carrier generation via different defect states, as well recombination and diffusion. The modeling was helpful to get insight into varying with excitation generation rates of holes and electrons and explained the main features of FWM kinetics and exposure characteristics.