Non-radiative and radiative properties of PLD-deposited polycrystalline GaN studied by UV ps-to-ns laser pulses

We have applied short laser pulses with a minimal pulse width of 5 ps to study the non-radiative and radiative carrier density decay in polycrystalline GaN. The GaN films are deposited by a cyclic pulsed laser deposition (PLD) technique at a relatively low substrate temperature of 600 °C on sapphire substrates. Results from photoluminescence decay and transient photocurrents are compared with respect to trapping, recombination, and transport of photogenerated carriers in polycrystalline GaN thin films.