Antimony as an amphoteric dopant in lead telluride

作者：Jaworski Christopher M^*; Tobola Janusz; Levin E M; Schmidt Rohr Klaus; Heremans Joseph P

来源：Physical Review B, 2009, 80(12): 125208.

DOI：10.1103/PhysRevB.80.125208

We elucidate the amphoteric nature of antimony as a dopant in PbTe. Band-structure calculations show that Sb substituting for Pb is a donor and that Sb on the Te site is an acceptor giving rise to a large excess density of states (DOS). Experimentally, in Te-rich Pb(1-x)Sb(x)Te samples, (125)Te NMR spectroscopy shows that Sb substitutes for Pb and transport data reveal that it then acts as a simple donor. In Pb-rich PbSb(x)Te(1-x) samples, (125)Te NMR shows that little Sb substitutes for Te when samples are prepared above 770 K and then quenched; (207)Pb NMR shows four types of charge carriers, but only a majority hole and a minority electron contribute to transport. Sb acts as an acceptor in PbSb(x)Te(1-x), but the large DOS calculated must correspond to a large concentration of localized holes and the Seebeck coefficient is not enhanced.

• 出版日期2009-9