LAUSR

Abstract The presence of impure phases affects thermoelectric properties of material by introducing two types of conduction (n and p type) in a thermoelectric system. This manuscript focuses on investigating the influence of impurity phases on structural and electrical properties of solvothermal synthesized CoSb3 system. X-ray diffraction and Rietveld analysis unveiled that incrementing the synthesis temperature and duration, increases the probability of attaining a pure phase CoSb3 skutterudite. The crystallite size of samples obtained from Sherrer's formula is in the range 43–45 nm. The Rietveld refinement further showed that percentage of cubic CoSb3 phase is highest i.e. 98% having synthesis profile of 260 ∘C for 48 h. In contrast, 24 h synthesized sample at 260 ∘C shows the presence of impure phase Sb2O3 rods of micron size and FESEM analysis also indicated that average particle size varies from 56 to 66 nm and shows spherical morphology. The Hall measurement of the samples revealed carrier concentration and mobility of the order of 10 17 − 18  cm−3 and 0.5–10 cm2V−1 s−1, respectively at room temperature. The electrical conductivity, from I-V measurement was around ≈ 121 S m−1 in purest synthesized sample. These investigation generalizes the effect of impurity phases on the figure of merit and optimizing for efficient thermoelectric system.