Structurally and mechanically tunable molybdenum oxide films and patterned submicrometer structures by electrodeposition

Graphical abstract: Display Omitted -- Abstract: 1.5 μm-thick molybdenum oxide films have been electrodeposited potentiostatically from 0.2 M Na₂MoO₄ electrolyte onto indium tin oxide (ITO)/glass substrates at pH = 1, 6 and 9. The influence of cetyltrimethylammonium bromide (CTAB) surfactant on films' adhesion, morphology, degree of porosity, molybdenum speciation, and crystallographic structure has been systematically investigated. The addition of CTAB (0.01 M) to the bath clearly improves film adherence to the substrate, reduces cracking, and increases crystallinity. This has an impact on the physical properties of the films. In particular, both hardness (H) and Young's modulus (E) increase, as determined from nanoindentation tests. The growth of ordered arrays of molybdenum oxide submicrometer structures, including pillars and stripes, by electrodeposition onto e-beam lithographed Au/Ti/Si substrates is also reported