Shisheng Lin, Haiping He, Z. Ye
Dec 4, 2008
Journal of Applied Physics
The authors report fabrication of aluminum monodoped ZnO (AlZnO) and aluminum-indium dual-doped ZnO (AlInZnO) nanorods arrays. Optical properties of AlZnO and AlInZnO nanorods are studied through temperature-dependent photoluminescence (PL) and PL excitation (PLE). Compared to AlInZnO nanorods, AlZnO nanorods possess better PL properties, as evidenced by a higher ratio of intensity of band-edge emission to green emission at 10 K and a higher PL intensity at room temperature. As supported by x-ray diffraction patterns, AlZnO nanorods also have higher crystallinity than AlInZnO nanorods. Indium doping induces a pronounced donor-acceptor pair transition of ∼3.22 eV at 10 K, the mechanism of which is discussed. Temperature-dependent energies of the A free exciton (FXA) and neutral donor bound exciton (D0X) are analyzed and the Einstein temperature is deduced to be ∼310 K. An activation energy of ∼8 meV is determined from the quenching of D0X as a function of temperature in AlInZnO nanorods. It is interpreted ...