Simultaneous enhancement in thermopower and electrical conductivity of SnTe-Te nano heterostructures

• Published in: Materials letters Vol. 302; p. 130414
• Main Authors: Singh, Satyendra, Kumar, Sushil, Venkatesh, R.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-11-2021; Elsevier BV
• Subjects: Carrier mobility; Electrical resistivity; Electrons; Enhanced electrical conductivity; Enhanced thermopower; Figure of merit; Heterostructures; Heterostructures growth; Materials science; Morphology; Nanomaterials; Rapid synthesis; Room temperature; Seebeck effect; Structural analysis; Tellurium; Thermal conductivity; Thermoelectric materials; Thermoelectricity; Tin tellurides; Rapid synthesis; Enhanced thermopower; Heterostructures growth; Enhanced electrical conductivity
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2021.130414

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•SnTe-Te heterostructures synthesized first time using microwave solvothermal method.•Room temperature thermoelectric power - enhanced by 55% when compared to nano SnTe.•Simultaneous enhancement in Seebeck coefficient and electrical conductivity.•Attributed to a significant enhancement in effective mass and carrier mobility.•SnTe-Te heterostructures are promising for large scale thermoelectric applications.
SnTe nanomaterials are investigated as the potential “Lead” free thermoelectric material owing to their low thermal conductivity induced enhanced figure of merit in comparison with their bulk counterpart. In this work, SnTe and its SnTe-Te heterostructures were synthesized for the first time by changing the protocol of heating time using microwave-assisted solvothermal processes. The confocal and scanning electron microscope images demonstrate the nano-flower-like morphology of SnTe-Te heterostructures. Multi-phase Reitveld refinement structural analysis exhibits a significant increase in tellurium occupancies, whereas elemental mapping confirms the presence of SnTe-Te heterostructure. Interestingly, room temperature thermoelectric power of SnTe-Te heterostructures (~60 μV/K) is increased by ~55% when compared to SnTe nanostructures (~45 μV / K). Simultaneous enhancement of both electrical conductivity and Seebeck coefficient are attributed to the increment of carrier mobility and effective mass respectively which is due to the novel strategy of SnTe-Te heterostructures formation that is promising for large scale p-type thermoelectric applications.