Visible room-temperature photoluminescence of AIN films, prepared by RF magnetron sputtering

Room-temperature photo luminescence (RT PL) has been observed from aluminum nitride (AlN) samples under continuous near UV (363.8 nm) and pulse UV (248 nm) laser excitations. The films were deposited by the radio frequency (RF) sputtering of Al target in argon-nitrogen-hydrogen (Ar: N-2:H-2) gas mixture. The interpretation of the PL origin is based on the results of the structural studies and electron spectrum investigations. The PL spectrum alteration is interpreted as due to variation in the electron spectrum and crystalline fraction of atomic structure under changing deposition conditions (N-2+H-2 flow rate and substrate temperature). Transient PL signal has been measured after short (20-25 ns) pulse excitation by the KrF laser. Long duration of transient PL (decay lifetime of 160+/-25 mus) has been detected in such experiments.