Electrodeposition of p-Type Sb2Te3 films and micro-pillar arrays in a multi-channel glass template

Abstract

Antimony telluride (Sb2Te3)-based two-dimensional films and micro-pillar arrays are fabricated by electrochemical deposition from electrolytes containing SbO+ and HTeO2+ on Si wafer-based Pt electrode and multi-channel glass templates, respectively. The results indicate that the addition of tartaric acid increases the solubility of SbO+ in acidic solution. The compositions of deposits depend on the electrolyte concentration, and the micro morphologies rely on the reduction potential. Regarding the electrolyte containing 8 mM of SbO+ and 12 mM of HTeO2+, the grain size increases and the density of films decreases as the deposition potential shifts from -100 mV to -400 mV. Sb2Te3 film with nominal composition and dense morphology can be obtained by using a deposition potential of -300 mV. However, this condition is not suitable for the deposition of Sb2Te3 micro-pillar arrays on the multi-channel glass templates because of its drastic concentration polarization. Nevertheless, it is found that the pulsed voltage deposition is an effective way to solve this problem. A deposition potential of -280 mV and a dissolve potential of 500 mV were selected, and the deposition of micro-pillars in a large aspect ratio and at high density can be realized. The deposition technology can be further applied in the fabrication of micro-TEGs with large output voltage and power.