The graphs showing the influence of the evaporation rate, R, of each material on
thermoelectric properties of the compounds are presented in Figure 12. The evaporation
flow rate ratio, R=FrTe/FrBi,Sb, is defined as the amount (in volume of the deposited film)
of tellurium (Te) divided by the amount of bismuth (Bi) - or antimony (Sb) - that arrives
the substrate during deposition. The highest power factor (PF) was obtained with a Bi
(or Sb) evaporation rate of 2 Ås-1 and a Te evaporation rate of 6-7 Ås-1, which
corresponds to an evaporation flow rate ratio in the range 3-3.5