Direct mapping of local coefficient in 2D materials nanostructures via scanning thermal gate microscopy

image of deconvolution of the thermovoltage maps of the rectangular graphene strip device

Researchers at Oxford, Lancaster and Delft collaborated to use the non-destructive method of scanning thermal gate microscopy to obtain high resolution 2-dimensional maps of the thermovoltage, in order to study graphene samples.

It is accepted that studying local variations in the Seeback coefficient of materials is important for understanding and optimizing their themoelectric properties, yet most thermoelectric meaurements are global over a whole device or material, thus overlooking spatial divergencies in the signal and the role of local variation and internal structure.

In this paper, published in 2D Materials, the researchers demonstrate the efficiency of this newly developed method by measuring local Seebeck coefficiency in a graphene ribbon and in a junction between single-layer and bilayer graphene.