The project aims to develop strategically structured semiconductor substrates for a range of applications, including; gas sensing, electrochemistry, and catalysis. The materials will target real-world utilisation, principally through providing resistance to both; wetting and chemical degradation. The project ultimate targets the design of a self-cleaning (superhydrophobic) gas sensors, able to function in challenging environmental conditions.
Semiconductors are commonly applied to chemical detection, and the facilitation of reactions, due to their electronic structure. The electronic properties of these materials are utilised in two main ways; (i) the presence of molecules at the surface of semiconductors can electronically perturbate these materials which is then detected (e.g. gas detection), (ii) the electronic levels can also be manipulated to drive chemical reactions (e.g. electrochemistry). In addition, the unique I-V behaviours such as resistive switching or novel device configurations based these materials will be investigated.
These materials (particularly gas sensors) require the target molecule to make direct contact (physisorption/chemisorption) with the semiconductor substrate. Consequently, they are susceptible to surface contamination, as access to the surface of the material may be blocked. Resulting in a reduction in device sensitivity as the amount of contamination increases. This is a key concern for the long-term use of these materials, whereby a progressive sensitivity loss is continually considered, or special measures (including; regular device cleaning, or protective housing) must be taken.A semiconductor material able to remain functional over long periods, without these specific concerns, will provide a leap in versatility/applicability.
The project targets the use of superhydrophobic materials in combination with semiconductors to prevent surface contamination. Superhydrophobic materials demonstrate self-cleaning properties, whereby water droplets (e.g. rain) remove surface contaminants by a mechanism termed; ‘the Lotus effect’. This would enable continual gas sensing functionality (or device functionality) with periodic exposure to water flow across the surface. While also preventing wetting of the surface, which would also interfere with molecular sensing. Superhydrophobic materials require two surface properties; (i) a high surface roughness (micro/ nanoscale), and (ii) and inherently water repellent surface chemistry.
The proposed architecture will utilise highly rough semiconductor materials, with a hydrophobic modification to the surface chemistry – resulting in superhydrophobic properties. The target material demonstrates partial functionalisation of the semiconductor material, limited to the top surface. This provides elevated water repelling properties, while maintaining a portion of uncoated semiconductor surface for continued functionality (e.g. gas sensing).
This project is a part of a 4-year dual PhD programme between National Tsing Hua University (NTHU) in Taiwan and the University of Liverpool in England. It is planned that students will spend (INSERT PATTERN OF STUDY) 2 years at NTHU, followed by 2 years at the University of Liverpool.
Both the University of Liverpool and NTHU have agreed to waive the tuition fees for the duration of the project and stipend of TWD 10,000/month will be provided as a contribution to living costs (the equivalent of £280 per month when in Liverpool).
When applying please ensure you Quote the supervisor & project title you wish to apply for and note ‘NTHU-UoL Dual Scholarship’ when asked for details of how plan to finance your studies.
For academic enquires please contact Prof. Yu-Lun Chueh ([email protected]
) or Dr Colin Crick ([email protected]
For enquires on the application process or to find out more about the Dual programme please contact
MARJ OR SHIRLEY – TBC
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