Enhanced thermoelectric properties of n-type Bi2Te2.7Se0.3 materials by TiO2 ceramic nanoparticle dispersion-induced energy filtering effect

Due to their superior thermoelectric capabilities, Bi 2 Te 3 -based materials have long been a popular area of study in the thermoelectric field. However, further advancements in the energy conversion efficiency of Bi 2 Te 3 -based thermoelectric modules are constrained by the low figure of merit of n -type Bi 2 Te 3 . Here, we describe an efficient method for enhancing the electrical and thermal characteristics of n -type Bi 2 Te 2.7 Se 0.3 (BTS) material by dispersing TiO 2 ceramic nanoparticles (NPs) in the matrix of the BTS. In more detail, the energy potential barrier, created by the matrix and the addition of TiO 2 NPs, causes an energy filtering effect, which in turn raises the Seebeck coefficient. The lattice thermal conductivity is decreased as a result of dislocations at the TiO 2 /BTS interface and an increase in grain boundary density brought on by the fine grain strengthening of TiO 2 ceramic NPs. Last but not least, the ZT max for the BTS + 3 wt% TiO 2 sample increased to 1.31, representing an improvement of 52% over the pristine sample. Additionally, at a maximum temperature differential of 150K, we have built a thermoelectric module with a power output and energy conversion efficiency of 7.2 W and 5.9%, respectively. This study introduces a viable approach towards the rational design of advanced n -type Bi 2 Te 2.7 Se 0.3 materials.