Control of the Deposition Ratio of Bi2Te3 and Sb2 Te3 in a Vacuum Evaporator for fabrication of Peltier Elements

Abstract

This article reports the main problem and the corresponding solution of the co-evaporation of Bi2Te3 and Sb 2Te3 films for the fabrication of Peltier elements. This main problem consists in the control of the deposition rates of the two elements: Bi or Sb and Te, which have very different vapor pressures. The control of the deposition ratio was achieved by means of a PID controller, which permitted the fabrication of thin-film Peltier elements that produce a temperature gradient in the order of 2degC between their hot and cold junctions, when measured at free air conditions