Event Details

Condensed Matter seminar

The field of molecular electronics has long focused on the isolation and characterisation of single molecular junctions to study their fundamental electrical and thermal transport properties. For practical applications, these tailored molecules need to be incorporated into scalable ultra thin-film architectures on surfaces and at interfaces.Since the discovery of the thermoelectric effect in molecules by Reddy et al. in 2007 [1], the field has drawn a lot of attention from the scientific community; as a potential solution to key energy problems such as recovering waste heat from microelectronic devices or server farms.Moreover, probing the thermoelectricity of molecular architectures in metal junctions is an interesting topic, not only due to its potential in the field of molecular electronics and energy conversion devices fabrication [2-3] but also because it aids in the understanding of the fundamental relationship between the transport and structural properties of molecules [4-7]. In this talk, I will discuss an optimised methodology to study and characterise the electric transport and thermoelectric properties of molecular junctions by using a modified scanning probe technique known as conductive probe AFM (C-AFM).The thermoelectricity of different molecular junctions was measured using thermoelectric force microscopy (ThAFM), which integrates C-AFM with a heating element. Thin-film samples, made by molecular self-assembled monolayers (SAMs) and Langmuir-Blodgett deposition (LB), enabled 10-100 junctions to be created by controlling the force applied by the tip.I will also show how it is possible to control the thermoelectric properties of the molecular π-system by varying the thickness of the film or by “chemical doping” of the molecular units. This is a potential alternative to using electrostatic gating to control the alignment of the energy levels in the molecules.

If you have not received a Teams link for this event and would like to attend, please contact Professor Robert Young.