Mn掺杂ZnO柱的结构及光学性质

Structural and Optical Properties of Mn-doped ZnO Nanocolumns Grown by Cathodic Electrodeposition

采用电化学沉积方法在Si（111）衬底上制备出了Mn掺杂的ZnO柱,长度约为500600 nm,直径为200300 nm。通过XRD和XPS的表征可以判断出：Mn2＋离子代替部分Zn2＋离子进入了ZnO晶格,Mn离子的掺杂量为2%。样品的共振拉曼谱表明：由于Mn2＋离子进入了晶格,导致ZnO的1LO和2LO光学纵向声子向高频移动。在He-Cd激光器325 nm激发下,可以观测到光谱中存在两个发光谱带,分别位于可见区和紫外区。

Application of semiconductor nanostructure materials in devices has become one of the major focuses in recent nanoscience researches.And considerable effort has been made to fabricate the zinc oxide（ZnO）.With its large exciton binding energy of 60 meV,ZnO has been recognized as a promising photonic material in the shortwavelength region with significant potential in laser emission,field emission,and nanoscale heterojunction.Electrodeposition of polycrystalline semiconductor is mainly used for photovoltaic and optoelectronic applications.It is a simple and inexpensive technique compared to molecular beam epitaxy（MBE）,liquid phase deposition（LPD）,or chemical vapor deposition（CVD）.Granular systems consisting of nanoscale ferromagnetic clusters imbedded in a semiconductor matrix have been recently realized using low temperature MBE by ion implantation/annealing,or simple annealing.As an alternative to this approach,we have investigated the electrodeposition of semiconductor-based systems consisting of Mn2＋ in a ZnO semiconductor host.In this paper,we present the results of structural and optical properties of Mn doped ZnO nano columns electrodeposited onto p-type Si（111） substrates.Mn2＋-doped ZnO nanocolumns have been successfully grown by electrodeposition method on Si substrate.The columns are 500600 nm long with diameters ranging in 200300 nm.X-ray diffraction（XRD） and X-ray photospectroscopy（XPS） studies suggeste that the Mn ions dope into the ZnO crystal lattice.The concentration of Mn ions is 2%.In the resonant-Raman spectrum,phonon frequency shifts to higher wavenumbers.In photoluminescence spectrum,a weak ultraviolet emission and a strong visible emission are observed.