Scholarlink

<p>Thin and compact nickel oxide (NiO) films were grown by electrodeposition on two transparent conductive oxides (TCOs): (1) fluorine-doped tin oxide (FTO) and (2) tin-doped indium oxide (ITO) using a novel oxygenated aqueous nickel sulfate electrolyte. Different potentiostatic and galvanostatic electrodeposition conditions were selected from a potentiodynamic study where oxygen reduction reaction (ORR) supplied hydroxide ions that precipitated with Ni(II) species forming the desired films. The proposed oxygenated sulfate electrolyte was compared with the state-of-the-art electrolyte used in the electrodeposition of NiO films with applications in photovoltaic devices (i.e., nickel nitrate). A solution chemistry analysis revealed the main electroactive species involved in the formation of a Ni(OH)<sub>2</sub> layer before a post-deposition annealing that dehydrate most of the metal hydroxide to its oxide. A XPS analysis demonstrated that annealing increased the NiO surface fraction over Ni(OH)<sub>2</sub> compared with fresh samples but always keeping at least a 25% of the metal hydroxide. Two-step electrodeposition with annealing in between exhibited a true Mott–Schottky behavior under the following conditions: (1) a galvanostatic process on FTO and (2) a potentiostatic process on ITO. These samples exhibit a <i>p</i>-type semiconductor response with an acceptor density in the order of 10<sup>19</sup>&#xa0;cm<sup>−3</sup>. P-benzoquinone (p-BQ) was successfully applied as a novel redox target to assess the electron transfer blocking effect of NiO films. A significant inhibition of the reduction process was found similarly to that seen for TiO<sub>2</sub> films, usually characterized using the ferri/ferro redox couple showing an inhibition of the anodic process. This blocking effect is of the upmost importance to effectively work as hole transporting layer in photovoltaic devices such as photoelectrochemical cells as proven by a comparison among different photoelectrochemical responses of these NiO films coated with the CsPbBr<sub>3</sub> perovskite. These results broaden the scope of electrochemical methods for both synthesis and analysis of metal oxide films with application as either electron or hole transporting layers for solar devices.</p> Graphical abstract <p></p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Electrochemical deposition of compact thin films of NiO on ITO and FTO suitable for photoelectrochemical devices

  • 期刊论文

  • 发表日期：

    2026年6月29日

查看全文
  • Martín Faúndez,
  • Patricia Díaz,
  • Alfredo Caballero,
  • Ricardo Bozzo,
  • Francisco Martin,
  • Nicolás Rojas,
  • Gonzalo Riveros,
  • Daniel Ramírez

摘要

Thin and compact nickel oxide (NiO) films were grown by electrodeposition on two transparent conductive oxides (TCOs): (1) fluorine-doped tin oxide (FTO) and (2) tin-doped indium oxide (ITO) using a novel oxygenated aqueous nickel sulfate electrolyte. Different potentiostatic and galvanostatic electrodeposition conditions were selected from a potentiodynamic study where oxygen reduction reaction (ORR) supplied hydroxide ions that precipitated with Ni(II) species forming the desired films. The proposed oxygenated sulfate electrolyte was compared with the state-of-the-art electrolyte used in the electrodeposition of NiO films with applications in photovoltaic devices (i.e., nickel nitrate). A solution chemistry analysis revealed the main electroactive species involved in the formation of a Ni(OH)2 layer before a post-deposition annealing that dehydrate most of the metal hydroxide to its oxide. A XPS analysis demonstrated that annealing increased the NiO surface fraction over Ni(OH)2 compared with fresh samples but always keeping at least a 25% of the metal hydroxide. Two-step electrodeposition with annealing in between exhibited a true Mott–Schottky behavior under the following conditions: (1) a galvanostatic process on FTO and (2) a potentiostatic process on ITO. These samples exhibit a p-type semiconductor response with an acceptor density in the order of 1019 cm−3. P-benzoquinone (p-BQ) was successfully applied as a novel redox target to assess the electron transfer blocking effect of NiO films. A significant inhibition of the reduction process was found similarly to that seen for TiO2 films, usually characterized using the ferri/ferro redox couple showing an inhibition of the anodic process. This blocking effect is of the upmost importance to effectively work as hole transporting layer in photovoltaic devices such as photoelectrochemical cells as proven by a comparison among different photoelectrochemical responses of these NiO films coated with the CsPbBr3 perovskite. These results broaden the scope of electrochemical methods for both synthesis and analysis of metal oxide films with application as either electron or hole transporting layers for solar devices.

Graphical abstract