Derivés azotés des polyoxometallates (des briques élémentaires vivantes)

PARIS-BIUSJ-Thèses (751052125) / SudocPARIS-BIUSJ-Physique recherche (751052113) / SudocSudocFranceF

Study of the Functional Properties of ITO grown by Metalorganic Chemical Vapor Deposition from different Indium and Tin Precursors

International audienceFunctional properties of tin doped indium oxide (ITO) layers grown by MOCVD from different indium and tin precursors are investigated. Selected indium precursors are In(acac)3, In(tmhd)3 and InMe2OtBu, and tin precursors are DBTDA and Sn(acac)2. ITO layers are optically and electrically characterized to determine the better doping conditions. Differences in electrical properties of ITO layers are found when using InMe2OtBu, as compared to In(acac)3 and to In(tmhd)3. The best films present a resistivity of 2.5 × 10−4 Ω cm and a transmittance higher than 84% for high deposition temperatures (T ⩾ 600 °C). The nature of tin precursors modifies the optimal doping at which these characteristics are achieved. When doped by DBTDA optimal doping is 8 at.%, therefore close to the solubility limit of tin in In2O3 matrix; but when using Sn(acac)2, or In(acac)3/DBTDA combination, best functional characteristics are obtained for the maximal doping content obtained, i.e. 2.5 at.%. For optimized conditions, the resistivity decreases when deposition temperature increases except when using the couple InMe2OtBu/DBTDA without oxygen addition during deposition. For this combination of precursors a resistivity of 1 × 10−3 Ω cm is obtained at a deposition temperature of 350 °C and remains constant up to 600 °C. Only the films obtained from InMe2OtBu/DBTDA are crystalline state at a deposition temperature of 350 °C

Influence of precursor nature on the thermal growth of Tin-Indium oxide layers by MOCVD

International audienceWe investigate three indium and two tin precursors for metalorganic chemical vapor deposition to highlight their influence on the resulting indium oxide or tin doped indium oxide (ITO) layers. Selected indium precursors are In(acac)(3), In(tmhd)(3) and (InMe2OBu)-Bu-t, and tin precursors are DBTDA and Sn(acac)(2). Acetyl acetonate ligand is identified to induce an organic contamination in the In2O3 and ITO layers when depositions are performed with In(acac)(3) or Sn(acac)(2) as precursor. The growth kinetic is also investigated. (InMe2OBu)-Bu-t presents a higher deposition rate and reactivity; besides the grown films crystallize at lower temperature as compared with the two other indium precursors. Moreover, it is the only studied indium precursors which allow synthesizing In2O3 and ITO layers without oxygen addition. Depending on the atmosphere, layers synthesized with (InMe2OBu)-Bu-t present different morphology. In particular, without oxygen addition, a (222) preferential orientation is detected by X-ray diffraction and correlated to a morphology composed of bundles of nanowires as evidenced by transmission electronic microscopy. Concerning tin doping in the ITO layer, incorporation is more efficient when using DBTDA than Sn(acac)(2) and when combined with (InMe2OBu)-Bu-t than with In(tmhd)(3) and In(acac)(3). (C) 2013 Elsevier B.V. All rights reserved