Annealing effect on the structural, optical, and electrical properties of CuAlO(2) films deposited by magnetron sputtering

作者:Lan W*; Cao W L; Zhang M; Liu X Q; Wang Y Y; Xie E Q; Yan H
来源:Journal of Materials Science, 2009, 44(6): 1594-1599.
DOI:10.1007/s10853-008-3229-2

摘要

We studied the annealing effect on the structural, optical, and electrical properties of sputtered CuAlO(2) films. It is found that the crystallinity of CuAlO(2) films is improved with increasing the annealing temperature in N(2) ambient, and the film annealed at 900 A degrees C presents the excellent preferred (001) orientation in X-ray diffraction patterns as well as Raman scattering signals, A (1g) and E (g). The optical absorption edge of the annealed films is observed extremely complex. Four optical bandgaps estimated are distributed in the following energy regions: similar to 3.00, similar to 3.15, similar to 3.50, and similar to 3.75 eV, which might originate from different direct transitions in CuAlO(2) energy band, respectively. For the annealed CuAlO(2) films, the resistivity decreases three orders of magnitude, which is attributed to the contribution of intrinsic defects, Cu vacancy and interstitial oxygen.