Effects of current stressing on the p-Bi2Te3/Sn interfacial reactions

The Sn/p-Bi2Te3/Sn sandwich-type sample was current stressed with a density of 150 A/cm2 to investigate the effects of current stressing on the p-Bi2Te3/Sn interfacial reactions. Asymmetrical heating phenomenon was observed at the anodic Sn/p-Bi2Te3 (50 °C) and cathodic p-Bi2Te3/Sn (120 °C) interfaces due to the Peltier effect. Besides the Peltier effect, the electromigration effect also influenced the growth of the SnTe phase and therefore polarity growth behavior was observed at the two interfaces. The growth of the SnTe phase at the cathodic p-Bi2Te3/Sn interface was accelerated because Peltier and electromigration effects drove more Sn atoms (dominant diffusion species) for the phase growth. By measuring the electromigration-induced atomic flux of Sn, the product of diffusivity and effective charge number (D × z*) was calculated to be 6.3 × 10−9 cm2 s−1 at 120 °C.