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 degreesC 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. (C) 2004 Elsevier B.V. All rights reserved.