Effecting the thermoelectric properties of p-MnSi1.75 and n-Mg1.98Ag0.02Si module on power generation

Higher manganese silicide (p-MnSi1.75) and silver doped magnesium silicide (n-Mg1.98Ag0.02Si) were synthesized by hot press method in Ar atmosphere. Thermoelectric properties of p-MnSi1.75 and n-Mg1.98Ag0.02Si at temperature ranges of 300–473 K in air were measured. The thermoelectric elements size of 2 × 2 × 3 mm3 were compacted on top and bottom with Ag powder by hot press method to ensure a good connection with the electrode. Cu plate of 0.3 mm thick was used for electrode of the thermoelectric cell (1 pair) and module (30 pairs) because of its high conductivity. Alumina substrate size of 50 × 50 × 1 mm3 with good thermal conductivity was used. The dimensionless figure of merit (ZT) of MnSi1.75 and Mg1.98Ag0.02Si show a high value of 0.23 and 0.02 at 473 K, respectively. The highest power output of 1 pair and 30 pairs show a value of 19.71 μW and 4.69 mW at different temperature of 140 K. •The thermoelectric properties are very importance for generate electrical power of thermoelectric module.•The Mg2Si has increased dimensionless figure of merit after doping by Ag 0.02 by molar.•The thermoelectric module of p-type MnSi1.75 and n-type Mg1.98Ag0.02Si have not been reported.•We decreased ohmic contact of thermoelectric module by using Ag layer on thermoelectric materials.