High Power Factor and Enhanced Thermoelectric Performance of SnTe-AgInTe2: Synergistic Effect of Resonance Level and Valence Band Convergence

• DOI: 10.1021/jacs.6b08382
• Publication Date: 2016-09-06T17:14:55Z
• Authors: Ananya Banik; U. Sandhya Shenoy; Sujoy Saha; Umesh V. Waghmare; Kanishka Biswas
• Keywords: Figure of Merit

Understanding the basis of electronic transport and developing ideas to improve thermoelectric power factor are essential for production efficient materials. Here, we report a significantly large ∼31.4 μW/cm·K2 at 856 K in Ag In co-doped SnTe (i.e., SnAgxInxTe1+2x). This is highest so far reported SnTe-based material, which arises from synergistic effects on structure improved electrical properties SnTe. play different but complementary roles modifying valence band In-doping introduces resonance levels inside bands, leading significant improvement Seebeck coefficient room temperature. On other hand, Ag-doping reduces energy separation between light- heavy-hole bands by widening principal gap, also results an coefficient. Additionally, enhances p-type carrier mobility. Co-doping yields synergistically enhanced over broad temperature range because synergy introduction states convergence have been confirmed first-principles density functional theory-based calculations. As consequence, achieved figure merit, zT ≈ 1, SnAg0.025In0.025Te1.05 K.