• Gayner, Chhatrasal
• Das, Malay K.
• Kar, Kamal K.
• Mallik, Iram

Abstract

<p>In this work, we have explored the effect of dopant concentration (copper (Cu)) on the thermoelectric performance of Cu doped lead selenide (Pb_1-xCu _xSe (0 x 0.1)). With increasing the dopant concentration, sign inversion of majority charge carriers takes place for x 0.04 due to the donor behaviour of Cu in the P-type pristine PbSe. The room temperature Seebeck coefficients of Pb_1-xCu_xSe with x = 0.01, 0.02, 0.04, 0.06 and 0.08 are observed to be 233, 337, -473.7, -392.5 and -257.6 μV K^-1, respectively as compared to that of 186.4 μV K^-1 of the pristine PbSe. This increment in Seebeck coefficient is the result of low carrier concentration and is not related to the resonance states created by Cu dopant. At room temperature, the lattice thermal conductivity of pristine PbSe is 0.52 W m^-1 K^-1 while for Cu doped PbSe, it varies from 0.8 to 1.1 W m^-1 K^-1. Finally, with ZT of ∼0.59 and power factor of ∼700 at 500 K, Pb_0.98Cu_0.02Se exhibits the highest thermoelectric performance among the studied Pb_1-xCu_xSe systems. Owing to the high ZT and power factor, a single thermoelement of Pb_0.98Cu_0.02Se exhibits thermovoltage of &gt;100 mV at a temperature gradient of 200 °C.</p>

Topics

• impedance spectroscopy
• copper
• thermal conductivity