Phase transition induced thermoelectric properties of Cu2Te by melt growth process

•Cu2Te compound were prepared by melting of differently stacked Cu & Te powders.•Various phase transitions were observed which induced the variation in their thermophysical properties.•The sample exhibited all possible phase transitions of Cu2Te with lower thermal conductivity of 4.24 W/mK at 303 K. Cu2-xTe attracts the research attention because of its mobile copper cations which results the multiple phase transitions with respect to temperature. Herein, we report the phase transition induced thermal behaviour of Cu2Te in which the samples were prepared by melting of differently stacked Cu & Te powders {mixed (S1), Cu-Te-Cu (S2) and Te-Cu-Te (S3)}, respectively. S1 exhibited all the possible phase transitions of Cu2Te with 4.24 W/mK at 303 K which is 135% & 19% of increased κtot value while comparing to other samples. It is plausibly proposed to homogeneousness of samples whereas other samples could be formed with inhomogeneity caused by different stacking of Cu & Te melting process. The contradictory growth of Cu2Te planes was identified for S3 and it showed 57% & 49% of suppressed thermal conductivity than other samples due to inhomogeneity. The reaction kinetics has been discussed that adopts the variation in magnitude and trend of thermophysical properties of the samples.