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C 60 ‐doping of nanostructured Bi–Sb–Te thermoelectrics
Author(s) -
Popov Mikhail,
Buga Sergei,
Vysikaylo Philipp,
Stepanov Petr,
Skok Vasilii,
Medvedev Viacheslav,
Tatyanin Evgeny,
Denisov Viktor,
Kirichenko Alexei,
Aksenenkov Viktor,
Blank Vladimir
Publication year - 2011
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201127075
Subject(s) - thermoelectric effect , thermoelectric materials , materials science , nanocomposite , raman spectroscopy , doping , charge carrier , semiconductor , electron mobility , nanotechnology , thermal conductivity , optoelectronics , composite material , thermodynamics , physics , optics
New bulk nanocomposite thermoelectric materials composed from nanocrystallites of Bi–Sb–Te alloys covered by C 60 molecules have been synthesized and studied. The fullerene molecules provide thermal phonons blocking and particular charge transfer in the nanocomposite. The molecules act as electron traps, and thus decrease the density of free electrons in n‐type semiconductor and generate holes in p‐type materials. The capture of electrons is not accompanied by shifts of the Raman bands in C 60 spectra. The density of free charge carriers and their Hall mobility change nonmonotonically with the increase of fullerene content in Bi–Sb–Te–C 60 nanocomposites. The maximum value of thermoelectric figure of merit ZT = 1.15 was obtained in p‐type nanocomposite that is 30% higher than in the undoped starting material. The observed phenomenon provides new ways for transport properties optimization of thermoelectric materials and thermoelectric devices efficiency increase.