Modern technology has reached an unprecedented point enabling the creation of stable singular atomic layer structures known as two-dimensional materials. These layered systems represent an accessible platform for a deep understanding of the nanoscale physical phenomena, ranging from the fundamental physical fields up to more intricate paradigms like thermoelectricity or electromechanics. The properties of these materials can also be extensively modified, e.g., by stacking layers forming heterostructures or introducing defects that filter the charge transport. Nevertheless, to access such nanoscale systems and quantify their characteristics, powerful and precise tools are needed. Scanning probe microscopes can effectively accomplish this objective, given their capacity to probe a broad spectrum of physical phenomena with enhanced resolution while avoiding the modification of the studied materials. However, they are usually accompanied by analytical methods to deconvolute the intrinsic parameters that describe the structure’s performance.
This thesis provides novel pathways for an accessible analysis of the thermal, electronic and mechanical behaviour in low-dimensional materials, focusing on local probe characterization. Also, the interplay of such properties is investigated, yielding deeper insights into the fields of thermoelectricity, piezoelectricity and thermomechanics. Specifically, the anisotropic thermal behaviour of indium selenide and perovskite is probed with a novel scanning thermal microscopy methodology, which is also applied to quantify the thermoelectric efficiency of structures based on transition metal dichalcogenides. Local modulation of the thermovoltage is also achieved by the patterning of nanoconstrictions in two-dimensional layers. Finally, the electromechanical and thermomechanical response of nanoscale systems is probed in a Moiré superlattice and soft nanotube networks.
This work represents an improvement for the previously developed local probe characterization techniques, extensively describing new routes for enhanced physical phenomena quantification. It also provides new insights into the behaviour of nanoscale structures, expanding the current knowledge in fields such as heat management, thermoelectricity and piezoelectricity.