Surface functionalization of ZnO films by THIOL

In the present study, we have investigated the surface functionalization of dodecanethiol on ZnO film surface grown at three different oxygen partial pressure using pulsed laser deposition (PLD) technique. The thiol funcitonalized ZnO films have been examined by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), photoluminescence (PL) and vibrating sample magnetometer (VSM) measurement. XRD pattern show slight decrease in intensity of diffraction peak upon surface functionalization. The chemical bonding of ZnO with thiol has been confirmed by XPS measurement. The presence of S 2p3/2 peak centered about 163 eV suggests that proton has dissociated fromed thiol and form chemical bonding to the ZnO surface. PL measurements of thiol functionalized ZnO films show quenching of visible emission intensity relative to the unfunctionalized ZnO films. The quenching of visible emission suggests that thiol passivates surface defects via Zn-S bonding. Surface functionalization of ZnO films with thiol induces robust room temperature ferromagnetism as evidenced from VSM measurements.

[1]  Won-Jae Lee,et al.  Transparent conductive ZnO thin films on glass substrates deposited by pulsed laser deposition , 2005 .

[2]  Substrate mediated stabilization of methylphosphonic acid on ZnO non-polar surfaces' , 2012 .

[3]  Henryk Temkin,et al.  Size-dependent surface luminescence in ZnO nanowires , 2004 .

[4]  Jagdeep Singh,et al.  Adsorption of mercaptosilanes on nanocrystalline and single crystal zinc oxide surfaces , 2008, NanoScience + Engineering.

[5]  T. Frauenheim,et al.  Covalent functionalization of ZnO surfaces: A density functional tight binding study , 2009 .

[6]  X. Zu,et al.  Effects of annealing and dopant concentration on the optical characteristics of ZnO:Al thin films by sol–gel technique , 2006 .

[7]  J. M. Merino,et al.  Magnetic properties of ZnO nanoparticles. , 2007, Nano letters.

[8]  D. Gamelin,et al.  Electronic structure origins of polarity-dependent high-TC ferromagnetism in oxide-diluted magnetic semiconductors , 2006, Nature materials.

[9]  Qiang Sun,et al.  Ligand induced ferromagnetism in ZnO nanostructures. , 2008, The Journal of chemical physics.

[10]  T. Butz,et al.  Defect-induced magnetic order in pure ZnO films , 2009 .

[11]  Min Gyu Kim,et al.  Co-metal clustering as the origin of ferromagnetism in Co-doped ZnO thin films , 2004 .

[12]  S. Jeon,et al.  ZnO nanorod-coated quartz crystals as self-cleaning thiol sensors for natural gas fuel cells , 2009 .

[13]  Rongkun Zheng,et al.  Role of point defects in room-temperature ferromagnetism of Cr-doped ZnO , 2007 .

[14]  Sang Hyuck Bae,et al.  Relationship between photoluminescence and electrical properties of ZnO thin films grown by pulsed laser deposition , 2001 .

[15]  Robert F. Davis,et al.  Gold Schottky contacts on oxygen plasma-treated, n-type ZnO(0001̄) , 2003 .

[16]  J. Coey,et al.  Thin films: Unexpected magnetism in a dielectric oxide , 2004, Nature.

[17]  Fangting Lin,et al.  Doping concentration dependence of room-temperature ferromagnetism for Ni-doped ZnO thin films prepared by pulsed-laser deposition , 2006 .

[18]  J. Rodríguez,et al.  Fundamental studies of desulfurization processes: reaction of methanethiol on ZnO and Cs/ZnO , 2001 .

[19]  J. Vohs,et al.  Reactions of CH3SH and (CH3)2S2 on the (0001) and (000) Surfaces of ZnO. , 2005, The journal of physical chemistry. B.

[20]  K. Yuan,et al.  Enhancement of the ultraviolet emission of ZnO nanorods by terphenyl liquid-crystalline ligands modification , 2011 .

[21]  Jisun Im,et al.  Encapsulation of zinc oxide nanorods and nanoparticles. , 2009, Langmuir : the ACS journal of surfaces and colloids.

[22]  J. Jiang,et al.  Magnetism of O-Terminated ZnO(0001) with Adsorbates , 2009 .

[23]  Non-transition-metal doped diluted magnetic semiconductors , 2009 .

[24]  J. Jiang,et al.  Surface magnetism in amine-capped ZnO nanoparticles , 2009, Nanotechnology.

[25]  David P. Norton,et al.  Functionalizing Zn- and O-terminated ZnO with thiols , 2007 .

[26]  Tomoji Kawai,et al.  Magnetic and electric properties of vanadium doped ZnO films , 2001 .

[27]  M. García-Hernández,et al.  Evidence of intrinsic magnetism in capped ZnO nanoparticles , 2010 .

[28]  A. Maiti,et al.  Importance of O vacancies in the behavior of oxide surfaces: Adsorption of sulfur on TiO2(110) , 2002 .

[29]  C. Ventrice,et al.  Bulk-defect dependent adsorption on a metal oxide surface : S/TiO2(110) , 2001 .

[30]  Room temperature magnetism in semiconducting films of ZnO doped with ferric ions , 2006 .

[31]  Jun Ding,et al.  Thiol-capped ZnO nanowire/nanotube arrays with tunable magnetic properties at room temperature. , 2010, ACS nano.