Determining Microwire Morphology and Current Transient Trends from Single Microwire Electrodeposition

Tuesday, 26 May 2015: 17:40
Williford Room C (Hilton Chicago)
T. Zhang, E. Fahrenkrug, and S. Maldonado (University of Michigan)
This presentation describes work on understanding and controlling the electrochemical liquid-liquid-solid (ec-LLS) process for the preparation of crystalline semiconductor materials. In this work, data are presented to test the hypothesis that the current-time transient collected during a potentiostatic ec-LLS deposition of Ge microwires contains useful details about the crystal growth. A photoresist pattern with a single hole was fabricated on top of a conductive support to make an ultramicroelectrode (UME) with a defined diameter ranging between 10 and 35 microns. These single-hole UMEs were filled with a liquid metal which acted as the electrode and crystal solvent in ec-LLS. Individual germanium microwires were then electrodeposited onto the liquid metal by chronoamperometry from an aqueous solution using a variety of different potential, temperature, and liquid metal conditions. Current transients will be discussed in relation to their correlation with morphological and crystallographic features of as-prepared Ge microwires. The prospects for real-time adjustment of microwire growth during an ec-LLS process will be presented.