Optical Properties of Heavily Aluminum-doped Zinc Oxide Thin Films Prepared by Molecular Beam Epitaxy

摘要

Aluminum (Al) doped ZnO (AZO) films were grown on sapphire substrate via oxygen radical assisted molecular beam epitaxy (MBE) technique. The results of XRD measurement and temperature dependence Hall measurement confirmed that the AZO films were typically highly degenerate semiconductor with good crystallinity. The optical properties of these films were investigated by photoluminescence (PL) spectra at RT and absorption spectra at 5 K. Strong band-edge emission was observed in the AZO films in spite of high carrier concentration more than 10~(20)cm~(-3). A sift of absorption edge to higher energy side and a gradual increase of the absorption was observed for the AZO film.