| AVS 62nd International Symposium & Exhibition | |
| Plasma Science and Technology | Monday Sessions |
| Session PS+EM-MoA |
| Session: | Directed Self Assembly and Plasma Synthesis of Novel Materials |
| Presenter: | Irem Tanyeli, FOM Institute DIFFER, Netherlands |
| Authors: | I. Tanyeli, FOM Institute DIFFER, Netherlands L. Marot, University of Basel, Switzerland D. Mathys, University of Basel, Switzerland M.C.M. van de Sanden, FOM Institute DIFFER, Netherlands G. De Temmerman, ITER Organization |
| Correspondent: | Click to Email |
Many applications, such as energy harvesting, energy storage, optoelectronics, demand nanomaterials and/or nanostructured surfaces for an enhanced activity. Various techniques, which can be grouped under top-down and bottom-up approaches, exist and are worked on by many researchers in order to fulfill the demands of these applications. There are some critical requirements that needs to be satisfied by nanostructures before being implemented in any application, such as high porosity, good contact between different crystallites and good electrical conductivity. Standard nanostructuring approaches, such as wet-chemical processing, can give very homogeneous particle sizes, but the contact between the particles is often poor and a necking treatment is needed to alleviate this limitation. In this study, Helium ion induced nanostructuring is proposed as an efficient technique. This top-down approach provides a good control over morphology, high porosity, good conductivity and it enables post processing, such as oxidation and nitridation.
Metal surfaces are exposed to pure Helium plasma under extreme ion flux (in the range of 1023 m-2s-1) and low ion energy (< 100 eV) conditions at Pilot-PSI, linear plasma generator. Different surface modifications on various metals, such as iron, titanium, copper and aluminum, are observed.1 Pillar like structures are formed on copper and aluminum surfaces, whereas fiber like nanostructures are observed on iron surface. Controlled nanostructure formation on tungsten and molybdenum surfaces has been reported.2 Consistently, nanostructure formation on iron surface has been controlled with surface temperature and ion fluence in this study.3 It has been known that metal oxides are good candidates to be used as photoelectrodes in photoelectrochemical cells. WO3 and α-Fe2O3 are two of the most widely studied photoanodes. Hence, Helium ion induced tungsten and iron nanostructured surfaces are oxidized to the desired phases to be tested in photoelectrochemical cells. 1mA/cm2 of photocurrent density for WO3 has been achieved.4
1 I. Tanyeli, L. Marot, D. Mathys, M. C. M. van de Sanden, G. De Temmerman, Sci. Rep. 5:9779-8, 2015.
2 G. De Temmerman et al., J. Vac. Sci. Technol. A, 30, 041306-6, 2012.
3 I. Tanyeli, L. Marot, M. C. M. van de Sanden, G. De Temmerman, ACS Applied Materials & Interfaces 6 (5), pp 3462-3468, 2014.
4 M. de Respinis, G. De Temmerman, I. Tanyeli, M. C. M. van de Sanden, R. P. Doerner, M. J. Baldwin, R. van de Krol , ACS Applied Materials & Interfaces 5 (15), pp 7621-7625, 2013.