Doping induced enhanced density of states in bismuth telluride

Abstract

Power factor enhancement through resonant doping is explored in Bi2Te3 based on a detailed first-principles study. Of the dopant atoms investigated, it is found that the formation of resonant states may be achieved with In, Po, and Na, leading potentially to a significant increase in the thermoelectric efficiency at room temperature. While doping with Po forms twin resonant state peaks in the valence and conduction bands, the incorporation of Na or In results in the resonant states close to the valence band edge. Further analysis reveals the origin of these resonant states. Transport calculations are also carried out to estimate the anticipated level of enhancement.

Comprehensive Insight into p-Type Bi2Te3-Based Thermoelectrics near Room Temperature

“…To make the RL conductive, the impurity state preferably has a s -or p -like character rather than a highly localized d -or f -like state. Namita et al, however, calculated that Po doping forms a double resonant state peak in the valence band and the conduction band, as well as the incorporation of Na or In results in the resonant states near the valence band edge based on detailed first-principles studies. Furthermore, the value of m d * in Nd 2 O 3 -introduced BST composites is increased from 0.84 m e to 1.02 m e , which reflects the formation of the local resonant distortion in DOS, thereby resulting in the enhancement of S (Figure c) .…”

A Review on Doped/Composite Bismuth Chalcogenide Compounds for Thermoelectric Device Applications: Various Synthesis Techniques and Challenges

“…First, the second and fourth atomic layers have zero density of state and have a gap in the Fermi level. 183 Each atom of Bi 2 Te 3 and Bi 2 Se 3 participates in the formation of a Dirac cone. P z states of bismuth atoms have the greatest influence on the formation of the surface state with linear dispersion, whereas a minor contribution is observed from selenium and tellurium atoms in p x and p y orbitals.…”

“…The contact pressure and the characteristics of the skin influentially modify this thermal resistance. 183,210 When the TEG is situated on body skin, the maximum power generated from a TEG decreases by 30%. 211,212 Heat spreaders improve wearable TEG performance.…”

Temperature dependences of thermoelectric properties of bulk SiGeAu composites

“…However, it is difficult to control three parameters (S, , and ) independently due to their correlation [1][2][3][4]. There are some approaches to overcome this difficulty: scattering control of carriers or/and phonon by introduction of nanostructures and modification of electronic states via band convergence or resonant level effect [27][28][29][30][31][32][33][34][35][36][37].…”