NanoScience Colloquium by Prof. Dr. Thomas Hannappel, TU IImenau, Germany

Speaker: Thomas Hannappel, Institute of Physics, Technische Universität Ilmenau, Germany
 

Abstract:

Converting sunlight directly into chemical fuels such as hydrogen is a promising route toward sustainable energy storage. Photoelectrochemical water splitting based on semiconductor materials can, in principle, achieve high efficiencies, particularly when using advanced III-V semiconductor systems.

In this context, semiconductor nanowires (NWs) offer unique opportunities compared to conventional planar structures. Their geometry enhances light absorption through optical antenna effects, supports efficient charge separation, and enables the integration of high-performance III-V materials on silicon platforms. At the same time, their large surface area provides abundant active sites for interfacial reactions with the electrolyte.

However, these advantages come with challenges: the high surface-to-volume ratio also makes NW-based systems particularly sensitive to corrosion and interfacial degradation under operating conditions. Understanding and controlling these processes is therefore essential for achieving stable device performance.

The seminar talk will discuss how photoelectrodes with NW geometry, defect density, and surface chemistry influence both efficiency and stability. Particular emphasis will be placed on interfacial engineering and passivation strategies, providing general insights into the design of robust semiconductor–electrolyte systems for solar fuel generation.

Adv Energy and Sustain Res  

Solar RRL