Platform for Simultaneous Low-Dimensional Thermoelectric and Optoelectronic Characterization: Identifying Holey Sige Nanoribbons

The objective of this project is to develop an advanced platform for simultaneous low-dimensionalthermoelectric and optoelectronic characterization. Holey SiGe nanoribbons are fabricated by nanospherelithography and monolithically integrated onto a combined thermoelectric and optoelectronic platform. Thenanoribbon dimensions and pitch parameters can be precisely controlled during fabrication. In addition,monolithic contact within the platform eliminates the contact resistance between the SiGe nanoribbon and themeasurement platform. Besides material characterizations, thermoelectric characteristics in holey SiGenanoribbons are systematically investigated. We further utilize pulsed laser deposition (PLD) technique todecorate silicide/germanide nanoparticles onto holey SiGe nanoribbons to enhance phonon scattering andincrease the ZT value. Furthermore, scanning photocurrent microscopy (SPCM) is employed to study thephotoresponse mechanism and its characteristic features. We also collaborate with the research group atWarsaw University of Technology, Poland to clarify the interrelationship between various low-dimensionstructural parameters and the overall thermoelectric properties by using first principles and simultaneously tooptimize the thermoelectric conversion efficiency of the material systems. The goal of this project is toachieve the thermal conductivity less than 3 W/mK and the ZT value higher than 1.2 in holey SiGenanoribbons. The combined thermoelectric and optoelectronic platform developed in this project is applicableto a broad range of nanomaterials to elucidate their fundamental thermoelectric and optoelectronic propertiesand to evaluate their feasibility when applied in thermoelectrics and optoelectronics.