Impact of melt solidification rate on structural and thermoelectric properties of n-type Bi2Te3 alloy

Polymer-mixed Sb2Te3/Te nanocomposites exhibiting p-type to n-type conduction reversal and thermal conductivity reduction

“…The single parabola band (SPB)-APS approximation is used to determine the L values from the S values. [40][41][42][45][46][47]. The κ c shows a similar trend of electrical conductivity, the decrease in carrier thermal conductivity with increasing temperature.…”

“…This might be caused by the interaction of the scattering mechanisms known as grain boundary/interfacial (metal-semiconductor) potential barrier scattering and acoustic phonon scattering (APS). [ [39][40][41][42]. The pristine Sb 2 Te 3 sample shows a higher electrical conductivity value of 70 × 10 3 S m −1 compared to other polymer mixed samples.…”

“…From figure 6(a), the polymer mixed samples show a lower electrical conductivity due to hindrance in the transport of electrons between the metal and polymer interface. At a specific temperature, the observed fluctuation in the electrical conductivity value is directly related to the variation in carrier concentration (n c ) and carrier mobility (μ) and is represented as σ = n c eμ [41,42]. The Hall measurements were performed for all the samples at room temperature and the measured Hall mobility and carrier concentration values were presented in table 1.…”

“…Figure 6(e) shows how thermal conductivity varies with temperature (κ c ). In the case of narrow bandgap materials, i.e., Sb 2 Te 3 and Bi 2 Te 3 , the total thermal conductivity is the sum of carrier (κ c ), phonon (κ p ), and bipolar thermal conductivity (κ b ), i.e., it can be expressed as κ T = κ c + κ p + κ b [39][40][41]44]. At low temperature, below 423 K, κ b is negligible.…”

“…The κ c value is estimated from Wiedemann-Franz relation κ c = LσT, L is the Lorenz number in this case. [39][40][41]44]. The single parabola band (SPB)-APS approximation is used to determine the L values from the S values.…”