Photoluminescence and its time evolution of AlN thin films

We report the room temperature photoluminescence measurements of AlN thin f ilms stimulated by above-band-gap pulsed light excitation. Two AlN thin fil ms with different composition and structure were studied. One AlN film, pre pared by pulsed laser deposition from sintered aluminum nitride ceramic tar get, contains oxide impurities. The other one, prepared by plasma assisted reactive pulsed laser deposition from pure aluminum metal target, is compos ed of pure AlN compound. Upon the irradiation of the samples by 193 nm exci mer laser pulses, both the as-grown AlN thin films luminesce in the ultravi olet and the green regions, peaked at 440 and 400 nm, respectively. We also examined the time evolution of the luminescence and found that the entire broad luminescence band decays non-exponentially at approximately the same rate. (C) 2001 Published by EIsevier Science B.V.