Nanoscale assembly of optoelectronic CdTe microwires using AC dielectrophoresis

This paper describes the effect of varying experimental parameters on the morphology and optoelectronic response of cadmium telluride quantum dot (CdTe QD) microwires formed using alternating current dielectrophoresis (AC-DEP). The thioglyocolic acid (TGA) capped CdTe QDs were assembled at room temperature across interdigitated electrodes (IDEs) under an applied electric field while simultaneously allowing solvent evaporation. The number of iterative rehydration steps required for bridging the microelectrode gaps of sizes 50–150 μm was found to depend on the electric field strength, particle concentration and electrode gap size. The frequency of the AC field applied, particle concentration and capping ligand were further optimized to regulate the fluorescence intensity, current density and chemical sensing behavior of the microassemblies. The overall process was found to be simple, rapid and scalable, and potentially holds promise for energy and sensing applications.